U.S. v. Cardenas - Conspiracy to Import Cocaine

24-2734 U.S. v. Cardenas In the United State s Cour t of Appeals For the Second Circuit A ugust T erm, 20 25 (Argued: Jan uary 14, 2026 Decided: February 18, 2026) Docket No. 24-2734 U NITED S TATES OF A MERICA, Appellee, –v.– J EY J AME S R OLDAN C ARDENAS, AKA Miller de Jes us Gutierrez Duran, Defendant – Appellant, M AURICI O R ENE G ARCIA Q UI MBAYO, AKA Tony, A KA M aurice, C LAUDI A I SA BEL M ERCADO S CAL ZO, A KA La Flaca, T ATIANA A NDR EA V ARGAS B ULLA, AKA Tat i, AKA To nia, AK A Tonya, O SCAR G OMEZ R OMERO, AKA Compa, J OSE A LFRE DO A GUAS O VIE DO, Defendants. * Before: C ARNEY, P ARK, and R OBI NSON, Circuit Judges. * The Cle rk of Court is respectfully directed to am end the cap tion as refle cted above.

2 Defendant- App ellan t J EY J AME S R OL DAN C A RDE NAS (“Roldan”) a ppeals from a judgment of the Un ited States Dist rict Court for th e Southern District of Ne w York (Ka plan, J.), entered after a jury tria l, co nvict ing h im of one count of conspiracy to import c ocaine into the United S tates in violation of 21 U.S.C. §§ 963 and 960(b)(1)(B). Although Roldan, a patrol - level police officer i n Col o mbi a, did not dispute that he participated in communications about a pr oposed cocaine export scheme, he contended that he la cked criminal intent because he believed he was helping t he Colo mbian N ational Police (“CN P”) arrange a seizure of the cocaine. On appeal, Roldan challenges the d istrict c ourt’s exclusion of undisputed evidence that the fello w CNP officer who recruited him into the scheme act ually did have relevant experien ce assist ing the CNP in successful drug sei zures. We conc lude tha t t he district court erred in excluding the challenged evidence. Th e evidence tended to corr oborate Roldan’s tes timony about key conversations with his colle ague that wer e directly relevant to his sta te of mind. Further, the evidence was not barred b y Federal Rule of Evidence 404(b). Because Roldan’s de fense turned on w hether he had crimina l inte nt and because a jury could cred it his evide nce on this point, the error was n’ t harmless. Accord ingly, we VACAT E the judgment of conviction and REMAND for furthe r proceedings consistent with this opinion. A LEXAN DER L I, Assistant United States Attorney (Sarah L. Kushner, Olga I. Zverovich, Assistant United States Attorneys, on t he brief), for Jay Cla y ton, United States Attorney for the Southern District of New Y ork, New York, NY, for Appellee. A LLEGRA G LASHAUSSER, Feder al Defenders of New York, Inc., App eals Bureau, New York, NY, for Defendant-Appella nt.

3 R OBINSON, Circuit Judge: Defendant- Appe llant Jey James Roldan Cardenas (“Roldan”) a ppeals from a fina l judg ment of convict ion ent ered in the United St ates Distric t Court for th e Southern Distr ict of New York (Kaplan, J.) following a jury trial, convict ing him of conspiracy to import cocai ne into the United States in violation of 21 U.S.C. §§ 963 and 960(b)(1)(B). Th e district court sente nced Roldan princ ipally to 165 months’ (nearly 14 years’) inc arceration, to be fol lowed by a five - year term of supervised release. Roldan, a patrol - leve l pol ice officer in Col o mb ia, doe s not dis pute that he partic ipate d in communications with Isi dro Vargas — a paid confident ial informant for the United States Drug Enforcemen t Admi nistration (“DEA”) posing as an internat ional drug trafficker —about export ing cocaine to the United States. Roldan cont ends, however, that he did so to help his cowork er in the Colo mbian Nationa l Police (“CNP”), Jos e Alfredo Aguas Ov iedo (“A guas”), set up a drug seizure. C onsistent w ith tha t understanding, Ro ldan’s defense at trial was th at he lacked t he req uisite criminal intent to join the c harged consp iracy because he beli eved he was assisti ng in an anti - narcotics operation directed at Vargas, rather than joinin g a drug- traff icking conspiracy with h im.

4 Among other issues, Roldan challenge s the distri ct court’s ex clusion of undisputed evidence that Aguas had pre viously t wice ass isted the C NP ’s anti - narcotics unit by pro viding information that led to drug seizu res. Roldan a rgues that the excluded evidence tended to cor roborate his test imony that Aguas told him that Aguas made money by p rovid ing t ips to the CNP, b ased on information given to hi m by sour ces, that led to seiz ures of drugs an d then tak ing part of the reward mo ney paid to the sources. Roldan conten ds that the distric t court exceeded its discre tio n in e xclu ding t he evidence and the error wasn’t harmless because i t went to the heart of hi s defense. We agree. Accordingly, we VACATE and R EMAND for further proceedings consistent with this opinion. BACKGROUND Below, we summarize the t rial record before turni ng to the pretrial ruling at the center o f this appeal. I. The Trial A. The Government ’s Evidence The government’s t heory was that Roldan engaged in a c onspiracy to smuggle dr ugs from C ol o mbia to the Un ited States by leveraging a “netw ork of corrupt associates” who “c ontrolled ev ery part of the [Cartagena ] airport,”

5 including the control tower s, camera systems, and forkl ifts. App’x 58. A s relevant here, the gov ernment int roduced the followin g evidence. DEA informant Var gas posed as a drug trafficker seek ing to buy dru gs in Colo mbia and trans port them ou t of the Car tagena airport t o the United States. Through various inte rmediaries, Vargas met Aguas, a patrol - level officer in the CNP, who reportedly “had a setup in the air, on land, and on the wa ter.” App’x 90. Aguas represented to one of these i ntermedia r ie s, who testi fie d at tr ial, that he had worked in anti - narcotics, suggesting to her that “ he had knowledge of the security protocols for detecting cocaine in the airport.” App’x 94. In May 2021, V argas met Aguas in Cartagena a t a meeting that Vargas believed would involve a “ colonel in the drug enforcemen t division” o f the CNP. App’x 236. At the meeting, however, Aguas appe ared alone; he told Var gas that he worked close ly with h is boss, a colone l. Aguas sa id he had his “own group ” and would hand le the log istics and secu rity of the coca ine deal, A pp’x 103, b ut Vargas insisted on meeting with Agua s ’s boss. That’s where Roldan came into the picture. After Varga s pressed to m eet with a h igher - r anking CNP offic ial, Aguas brought Roldan to a May 26, 2021, meeti ng with Vargas to discuss a plan to send co caine through the C artagena airport to Puerto Ric o and, ultimately, New York. Aguas told Vargas that Roldan

6 was a CNP major and Aguas’ s boss. During the meeting, Roldan emphasized that the mercha ndise shoul d be stored i n a warehouse controlled by Roldan’s team before it was loaded onto the plane. Roldan told Vargas that he wo uld “delegate” the log ist ical aspects of the operation to Aguas, but that he was “in charge of everythi ng” related to “ personnel ” and the “pol ice end of thi ngs” at the airport. App’x 128. Roldan emphasi zed that Agu as was his rig ht - han d man, with whom he had worked for se ven years. At that meet ing, Aguas set a price of $2,300 per kilogram of cocaine to facil itate the f ligh t. Vargas asked whether Roldan would want pay ment in Colombian pesos or American d ollars. Roldan responded, “ [w]hichever wa y,” before Ag uas clar ifie d that payment should be made in dollars. App’x 411 –12. Toward the end of the meeting, Vargas p laced $6,000 — provi ded to him by the DEA— in front of Ro ldan as “an advance.” App’x 143 –44. Roldan handed the money t o Aguas. Vargas doubted that Roldan was actual ly a police major. He tes tified that Roldan’s “uniform” appeared inconsisten t with that of a polic e major, descr ibing it as “frayed,” “in very bad cond ition,” and “missing s ome insignia,” and he expla ined that he came to refer to Ro lda n as “Mayor Falso,” or “Fake Major.” App’x 255–56, 300.

7 After the May 26 meeting, Vargas was introduced to a cocaine supplier. At the direction of the DEA, a confiden tial source who purpor ted to work for Vargas toured the supplier’s cocaine laboratory and se nt photographs of the laboratory to Vargas, who in t urn forwar ded the ima ges to Aguas and Roldan. On June 18, 2021, Var gas met again w ith Roldan, Aguas, and oth ers. Vargas informed R oldan an d Aguas th at he had agreed to b uy one th ousand kilograms of cocaine from the s up plier, and they discus sed the detai ls of the scheme to transport the drugs t hrough the Cartagena airport. Aguas took the lead, and Roldan s poke occasionally. For example, when Vargas aske d Roldan to c onf irm tha t the price for his serv ices rem ained $2,300 per kilogram, Roldan re sponded, “Yes, sir.” App’x 287. On June 29, 2021, Aguas (witho ut Roldan) met with Major Victor A lfonso Torres Valero (“Tor res”), who led an ant i - narcotics unit in th e CN P. 1 Aguas to ld Torres that he had re ceived information fr om a civilian source indicating that an airplane would be departing fro m Cartagena t o Central Amer ica carrying narcotics. He did not dis close his meet ings w ith Va rgas, and when Torres asked him if he would be interested in acting in an undercover capacity, he said he was 1 Torres did not testify at trial, but by stip ulation, the parties read to the jury a statemen t reflecting Torres’ s ex pected testim ony.

8 not. Torres said he would relay th e tip to t he DEA, and if t he DEA was in terested, it would organize the seizure of the drugs and p ay Aguas’ s informant. Torres instructed Aguas not to “ do anyth ing with the infor mation on his own.” App ’x 198. Ultimately, af ter a brief meeting with Aguas and the purported civi lian source, the D EA declined to work w ith th e source. On September 9, 2021, Vargas messaged Roldan thr ough Whats App, attachin g pho tographs of a three - kilogram samp le of coc aine he had purchased from the s upplier and wrote that he h ad ordered 1,000 additional “boxes,” or kilog rams. App’x 31 0. Vargas then as ked to speak with Roldan by phone. D uring the ensuing ca ll, Var gas asked whether Roldan had sp oken to Aguas abo ut the plan. Roldan responded that Ag uas was “keeping [him] up to speed.” App’x 312. When questioned, Roldan ass ured Vargas that he could be truste d and invited him to come with him to the anti - narcotics base. T he call concluded with Vargas confirming that R oldan preferred to be pa id in U.S. dollars. That was Roldan’s last communic ation with Vargas. On Februar y 19, 2022, Aguas and Roldan were arrested in Co lombia pursuant t o provisional arrest warrants requ ested by the United States. Roldan wa s extr adited to the U nited States in October of 2 022.

9 In add ition to the a bove evidence, the government called J uan Ayala, an investigator for the Office of the A ttorney Genera l of Colom bia. Ayala te stif ied that he was fa miliar with “how police pe rsonnel records and unde rcover - related records are maintained. ” App’x 345. He explaine d th at he had reviewed records from eight Colombian law enforcement agencies and di d not find an y records showing that either Roldan or Aguas had engaged in undercover work with those agencies at a ny po int in the ir careers. He als o did not receive “any records reflecti ng a sei zure” of $6,000 b y either Roldan or Aguas on May 26, 2021. App’x 346–47. Accor ding to Ayala, had Roldan and Aguas conduct ed such a seizure, they would have be en required to report it, and he would h ave found a related record. B. Defendant’s Evidence Roldan’s defense wa s that he never int ended to facilitate drug trafficking to the United S tates; r ather, he said, he thought he was parti cipating in an operation designed to set up a seizure of th e drugs by the CNP anti - narcotics unit. H e testif ied as follo ws. Roldan was a patrolman with the CNP. He wor ked as a horse - mounte d officer in rural ar eas in Colomb ia. In April 2021, Rold an met Aguas w hen Ag uas

10 was assigned to the same “ Banana Zon e ” 2 c ommiss ion as Roldan, an d Rol dan noticed tha t Aguas appeare d to b e “better off financially” tha n other patrol - lev el officers. App’x 38 6– 8 8. Aguas had a car, owned his weapo n, and had h igher - quality work gear. When Roldan aske d about this, Aguas explained that he worked at the anti -n arcotics base. Aguas reportedly sa id: I have a source wh o gives me drug info rmation, and I provide that informat ion to my bosses at the ant i - narcotics unit. My bosses speak with the DEA agents, and all of us work t ogether with that inf ormation, and then we carry out t he seizure. After the seizure is carried out, then they pa y a reward for that information. App’x 389. Agu as explained that h is source, who w as the direct reci pient of the reward, would pay Aguas a percentage. Roldan tes tified th at he was aware the CNP paid rewards fo r information lead ing to drug seizure s. One day when th ey were wor king, Aguas told Roldan t hat he had information from a source that a Mexican trafficke r (tha t is, Vargas) wa nted to move drugs through the Cart a gena airpor t. Aguas said he had spoken with his bosses at the anti - narcotics base and descr ibed a plan to persuade Vargas to place the drugs in a warehous e known to Aguas’s superiors, aft er which the drugs would be seized. A guas explained tha t he had already met with the Mexican 2 Roldan testified th at the Bana na Zone is an “inte nse” region “wit h many banana trees” located in Colombia’s Magd alena dep artment. App’x 3 79.

11 (Vargas) and that Vargas had asked to meet Aguas’ s boss bef ore committing to a deal. He aske d Roldan to “pretend to be A guas’ [s] boss and tell the Mexican that [he] was authoriz ing Aguas to do wh atever was neede d.” App’x 392. Rolda n testifie d that Aguas said he would receiv e a portion of th e reward, up to $7,000. Roldan further testified that Aguas brought h im to the CN P’s anti - narcotics base so Aguas could use the bathroom. T hey were admitted without a sear ch, the staff at the base kne w Aguas, and Aguas enter ed a room with a key he possessed. Roldan described his participation in the various commun ications proven by the governm ent as efforts to further the seizu re plan Aguas had described. So, for example, during t he May 26 meet ing when Roldan told Vargas and others tha t he was Aguas’ s boss, he understood that he was there to convince Var gas to trust Aguas and to go through with a plan t o place drugs in warehouses wher e they could be seized. W h en Roldan referred to staff througho ut the Cartagena airpor t as “my people,” App ’x 409, he was trying to convince Var gas that he was a major; he did not, in fact, control anyone at the a irpo rt. And when Vargas handed Rold an money at the end of that meeting, h e pass ed it along to Aguas be cause the plan as Roldan under stood it did not include taking any money. In fact, Roldan received none of that $6,000 payment from V argas.

12 Roldan testified that by the time of the June 18 m eeting, he ha d completed his te rm patr ollin g a longside Aguas in th e Banana Zone. When Aguas called to ask him to return to Cartagena f or another meet ing, he was hesitant, in part because he d idn’t have appropr iate clothing. Aguas sen t him mone y to b uy civili an c lothe s, loaned him a watch, and gave him s ome cologn e. Aguas also gave Ro ldan a password - protected cell phone with one contact listed in the WhatsApp a ccount by the name “Mexi,” p resumably short for “Mexican, ” meaning Vargas. App’x 417. Vargus sent pho tos to tha t account shortly b efore the meeting, apparently to val idate that the person with that pho ne was really Roldan. Roldan’s purp ose at that meeting was to give Vargas “more trust” so tha t he would deliver the drugs that wo uld be seized. App’x 417. With respect to the discussion at that me eting of Vargas’ s adv ance payment, Rolda n testified that he understood Aguas h ad arranged wi th his boss at the anti - na rcotics uni t to a llow him to receive that m oney. After the meeting, Rol dan returned to Agu as the phon e Aguas had given h im. Aguas then too k Rold an to me et two purported an ti - narcotics unit officers who were res ponsible for Ro ldan’s protect ion, which enhanced Roldan’s c onfidence that A guas was telling him the truth. Roldan testified that he received no updates from Aguas until September 2021. At t hat ti me, Roldan w as working at the Metropo litan Stadiu m where the

13 Colo mbian nation al football team was pla ying, when Aguas ca lled him and aske d him to pick up a ca ll from Vargas so that Vargas could hear h is voice. Because Roldan no longer h ad the phone that Aguas had given him, Aguas instr ucted Roldan to delete the WhatsApp account from his personal pho ne and reinstall the application wi th a number and security code associated w ith the fictitious major that he impersonate d. Using information that Ag uas gave him, Roldan the n messaged Vargas a nd in vited him to call. During Roldan’s brief conversat ion with Vargas, he assured Vargas that Aguas had kept him “up to spee d,” even though Aguas had not updated him since June. App’x 432. In response to Vargas questi oning whet her he could tru st Roldan, Roldan invited Vargas to go to th e anti - narcot ics base. He di d not actual ly work in an anti - narcotics base, but Agu as had told him to say that if Vargas expressed doubts a bout Roldan. After the call, Rold an u ninst alled the n ew WhatsApp account and reinstalled his o wn on his te lephone. That was his last communication w ith Vargas before his arrest. C. Summations In closing argumen t, Roldan’s counsel emphasized th at Roldan never intended to send drugs to the United States; rather, he int ended to seize them in Colo mbia. Roldan was a life long rura l patrolman who had f alsely posed as a h igh -

14 ranking major in the CNP, and the government provided no evidence that he w as capable of moving large quantities o f drugs throu gh the Cartagena a irport. He had never even worked in an airpo rt unit or in Cartagena. As to Ro ldan’s inten t, his c ounsel po inted out that Aguas took Roldan to the anti - narcotics base, and the two met with an anti -nar cotics officer after the June 18 meeti ng — both facts that reinforced Rol dan’s belief, co unsel urged, that he was engaged in an anti -narcotics- trafficking effort. He reminded the jury that Agu as had reported to Major Torr es that he had a civilian source who had pr ovided information abou t a plane that wou ld be departing fr om Cart a gena with narco tics inside, and that Ag uas and his source did meet w ith the DEA — evidence that suggests that, just as he told Roldan, Aguas was trying to set up a seizure with his anti - narcotics un it and the DEA. And counsel highlighted Roldan’s focus in the meeti ngs with Vargas on the n eed to put the drugs i n a warehouse — a nec essary step to facilitate a se izure. For its par t, the gove rnment argued th at Roldan “mad e [h is t estimo ny] al l up” and that “ther e was no unde rcover operation.” App ’x 537. The government emphasized that Col ombia has established procedures governi ng its undercover operations. Its witn ess, Ayala, “scoured ” Colombian gover nmental records “for any shred of evidence that [Roldan] or Jose Aguas” had worked “in an under cover

15 capacity” and found “[a] bsolut ely noth ing.” App’x 514. The government also stressed that “there were no records or r eports of the $6,000” provided by Vargas at the May 26 meet ing, suggest ing th at Roldan and Aguas k ept the money and never reported it. App’x 537. As the go vernme nt put i t: “Rea l undercover offi cers don’t ke ep money they seize from purporte d drug trafficker s. They fi le it in evidence. They fi le reports on it. Bu t none of that occur red here.” Id. II. Pretrial Motion and the Excluded Evidence The centra l issue in thi s appeal is w hether the dis trict court erred i n excluding certain proffered evidence fr om the trial. 3 Before trial, the government moved to exclude e vidence concerning Aguas’ s prior involvement with the CNP’s anti - narcotics unit, while th e defense sought to i ntroduce t hat same evi d ence. The contested evidence consisted of statements of CNP Major Torres that were recorded in the government’s int erview notes. 4 Torres was un available to test ify, and g iven the circumstances surrou nding his una vailab ility, the parties agreed to 3 B ecause we vacate Roldan’s con vic ti on on the basis that the district court did exceed its discr etio n in e xcl udi ng the statement at issue and that t he error was not harmless, we do not address Roldan’s arg uments regarding ot her evidentiary ruli ngs, his challenge to the ju ry charge, or his challenge to his se ntence. 4 Two Assistant United States Attorneys and two age nts from the DEA parti cipated in the intervi ew, along wit h an interp reter.

16 admit t he government’ s notes refl ecting the su bstance of Torres’ s expected testimon y to the exte nt the anticipated tes timony would be otherwise admissib le. As relevan t here, the admis sibil ity of t wo of Major Torr es’ s stateme nts was conteste d. First, the defe nse sought to introduce Ma jor T orres’ s s tatement that, following the May 26, 2021, meet ing, Aguas informed Major Torres that he had a civilian informant with information about a plane planning to depart from Cartagena carryin g narcotics. The government moved to excl ude this st atement as inad miss ible h ears ay. Second, the defense sought to in troduce Major Torre s’ s sta tement that Aguas had tw ice pre viously given information to the Major’s s ubordinates leading to successful cocaine seizures. The government moved to e xclude this statem ent on the basis t hat it constituted impermissibl e propensity evidence under Fe deral Rule of Evidence 404 (b). The distric t court de nied th e government ’s motion with respect t o the fi rst statemen t. The court explained that the defense offered the evidence not for the truth of the matter a sserted but rather for “the fact ” that Aguas told Major Torres there was a plane planning to leave Cartagena with dru gs, which made it “ somewhat more lik ely that he told [Roldan] tha t he was trying to fac ilita te the seizure (instead of h elping to export) the drugs ”— evidence b earing on Aguas’s

17 state of mind, which, the court said, “ in turn goes to [Roldan ’s] state of mind.” Spec. App’x at 5 –6. The dis trict court gr anted the govern ment’s moti on to ex clude the second statemen t — that Agu as had provided tips leading to prior drug seizures. Th e court wro te, without further elaboration, that it did so “ lar gely for the r easons stated in the government’s m otion.” Spec. App’x at 4. 5 Roldan’s challenge to this latter rulin g is a t the center of this appeal. DISCUSSION We review a district court ’s evidentiary ruli ngs with deference t o the district court. See U nited States v. Desposito, 704 F.3d 221, 233 (2d Cir. 2013). A d istric t court exceeds its dis cre tion where a rulin g is b ased o n “ an erroneous view of the law or on a clearly erroneous a ssessment of t he evidence, or if its dec ision cannot be located within the range of permissible decisions. ” United States v. Barret, 84 8 F.3d 524, 531 (2d Cir. 2017). 6 Even where a court errs, “e viden tiary rulin gs ar e 5 The district court suggested during the oral argum ent on the parties ’ respective pretrial motions that the statements were hearsay insofar as the Major lacked perso nal knowledge and wa s repeating what some o ther un identified person told him. The government did not make such a n argument in its pretrial motion, and does not press i t on appeal, for good reason. Th e record does not indicate how the Major knew about A guas’ s prior coordination with his subordinates on t wo occasions and is e ntirely cons istent with t he possibility t hat the Ma jor was aware o f Aguas’s effort s through record s regularly kept by his department. Fed. R. Ev id. 803(6). 6 In quotations from caselaw, this opinio n omits all internal quotation marks, foo tnotes, and citations, and accepts a ll alteratio ns, unless other wise noted.

18 subject to har mless error analysis. ” U nited States v. Me rcado, 5 73 F.3d 138, 141 (2d Cir. 2009). To prove that Roldan was guilty of the charge d conspiracy, “ the governmen t must demon strate that [he] possessed the specific intent to co mmit the offen ses that we re its ob jects.” Un ited States v. Anderson, 7 47 F.3d 51, 61 (2 d Cir. 2014). Thus, if the jur y concluded that Roldan truly b elieved he was partic ipat ing in a sc h eme to identify and s eize narcotics, rather than to dist ribu te or export them to the United Stat es, he would lac k the criminal intent required for conviction— even if he was ac ting imprope rly, unethic al ly, or eve n illeg ally in some oth er respect. O n appeal the government argues the dis trict co urt pr operly excluded the evidence under Federal Rule s of Evidence 404(b) and 403. We dis agree. We conclude that (1) th e exclu ded eviden ce was relevant because i t tended to corroborate Roldan’ s account of crit ical conversat ion s with Aguas be aring on Roldan’s state of mind, (2) as su ch, the s tatemen t did not con stitute propensity evidence and was i mproperly exclude d, and (3) the error was not harml ess.

19 I. Relevance Evidence is relevant if “(a) it has any ten dency to make a fact more or less probable than it wo uld be without the evi dence; and (b) the fac t is of consequence in determining the a ction.” Fed. R. Evid. 401. Roldan’s defense h inged almost entirely o n the jury credi ting h is testimon y that Aguas told him — and he believed —th at the purpose of their oper ation was to set up a l aw enforcem ent sei zure of the d rugs. Roldan did not dispute that he participated in meetings and co mmunications abou t exporting cocaine. Instead, he maintained that he lacked the requi site criminal i ntent because — based on Aguas’ s representat ion s— he believed those communications were part of an effor t to generate informat ion that would lead to a seizure that wo uld, in turn, yield financial benefits for Roldan. Ro ldan’s stated belief ste mmed in larg e part fr om the conversation in which Aguas descri bed to him Aguas’ s prior work with the CNP’s an ti - narcotics unit and the financial rewards Roldan und erstood that Aguas received f or providing tips that led to successful seizures. The exclu ded evidence — that Aguas had twice provided informat ion to the CNP’s anti - narcotic s unit leadin g to succes sful drug sei zures — tend ed to corroborate Ro ldan’s testimo ny tha t Agu as described to Rold an his p ast prac tice of giving the CNP in formation leading to drug seizures and then receiving a

20 portion of the reward money allocated to his sources. The fact that Aguas had, in fact, fa cilita ted two s eizures m ade Roldan’s claims tha t Aguas had de scribed to him facilitating such seizures more credible. The infere ntial chain here i s even stronger tha n the one we r ecognized in United States v. Detri ch, 865 F.2d 17 (2d Cir. 1988), as s upporting ad mission of challenged evidence. In that case, Detrich was found with narcotics concealed in the shoulder pads of a wedd ing suit when he arrived in New York on a f light from India. Id. at 18. He t old law enforcement officers that the s uit had been gi ven to him by an acq uaintance in India to deliver to a relative in the United St ates who was getting m arried the fol lowin g mo nth. Id. The d efense sought to introduc e a written st atemen t that relative gave whe n he was apprehended at the airport, where he had g one to collect Detrich and the suit. In that s tate ment, the relative said tha t he was pl ann ing to get married the following m onth. Id. at 19. The district c ourt ex cluded th e statement as hear say. Id. We reversed and h eld t he evidenc e admissible bec ause it tended to corroborate Detr ich’s account of his convers ation with his acqu aintance in In dia. Id. at 21. E vidence that the rela tive told the police he had marriage plans made it more likely that the acquaintance described those plans to Detri ch, as Detrich claime d, th us enhancing Detrich’s credibility with respect to his claim that he

21 thought he was doing an innocent favor for his acquaintance in India by del ivering a wedding s uit to th e relative. Id. S ignif icantly, we spec ifica lly n oted tha t the relative’s statemen t was admissible “ without regard to th e truth ” of the state ment — that is, even if the relative was not, in f act, planning to marr y — because what matte red was not whether th e relati ve actu ally p lanned to ge t married but whether Detrich beli eved that he did. Id. (emph asis added). As in Detrich, the excluded testimony here tend s to corr oborate Roldan’s testimony as to wh at Aguas told him. I t thu s be ars on Roldan’s intent by estab lish ing a stronger basis for hi s stated belief th at he and Aguas wer e engaging with Vargas for the purpos e of setting up a drug seizure. The evid ence, therefore, tends to make it more probab le th at Roldan believed he was assis ting a law - enforcemen t seizure rather tha n participating i n a drug - trafficking con spiracy, rendering i t relev ant under Rul e 401. Here, there is no dispute that Aguas did, in fact, facilitate two pri or successful drug seizures, so the corrob orative effect of the evidence i s even stronger than i n Detrich. II. Admissibility Unde r Rule 404(b) Thus understood, the excluded evidence doe s not run afou l of Federal Rule of Evidence 404(b). Under that Rule, otherwise relevant evidence of “any othe r crime, wrong, or act is not admissible to prove a person’s c h aracter i n order to

22 show” th at the pers on acted in accordance wi th th at charac ter “on a particular occasion.” Fed. R. Evid. 404(b) (1). S uch evidence may, however, be admitted for other purpo ses, inclu ding “provin g motive, op portunity, intent, preparation, p lan, knowledge, iden tity, absence of m istake, or lack of acciden t.” Fed. R. Evid. 404(b)(2). The governm ent argues that evidence of Aguas’ s prior involve ment in successful drug seizures by th e CNP would invite the jury to infer that Aguas acted in conformity with that prior good conduct in this case, in violation of Rule 404(b)’s prohibition on propensity evidence. 7 The governm ent reli es on a dec ision in which we affirmed the exclusion of evid ence the defendant offer ed of hi s prior lawful conduct t o suggest he acted lawfully on the char ged occasion. See United States v. Al Kassar, 66 0 F.3d 108, 123 (2d Cir. 2011). T hat case is inapposite. T he theor y of relevance outlined above does not re st on any inference s about Aguas’ s ac tual intent or plan. Instead, the ev idence is 7 A s to the government’s argument on appeal t hat the evidence was unduly prejudicial under Rule 403, the district co urt did not conduct a Rule 403 analy sis, and the government ’s pretrial motion seeking e xclusion of this component of the Torres stateme nt relied solely on Ru le 404(b). We decline to affir m the district court’ s evidentiary r uling on a basis the go vernment did not r aise before th e district court and the district co urt did not add ress. U nit ed Sta tes v. Figuero a, 548 F. 3d 222, 230 (2d C ir. 2008) (“Because we rev iew a Rule 403 decision for abuse of discretion, a nd since the district court did not exercise its di scretion on this basis or engage in a balancing process t hat we can review, we have no occasion to decide whether the evidence was proper ly excluded un der the Rul e.”).

23 relevant to corroborate Roldan’s testimon y about a conversation he had with Aguas that bears d irec tly on Roldan’s state of m ind. That is not a propensity - based inference, and Rule 4 04(b) does not bar the evidence. 8 III. Harmless Error Under Federal Rul e of Criminal Procedure 52, any “e rror, defect, irregularity, or var iance that does not a ffect substa ntia l rights mus t be disregarded.” Fed. R. Crim. P. 52(a). We wil l uphold a co nvic tion notwithstanding an evidentiary error only if it is “highly probabl e that t he error did not affect the verdict.” Unit ed States v. Dukagjini, 326 F.3d 4 5, 61 (2d Cir. 2003); see also Kotteakos v. United Stat es, 328 U.S. 750, 764 –65 (1946) (ex plain ing that reversal i s required unless the court is sure that the error “ did not influence the jury, or had but very s light effect”). In assessing harml ess ness, we consider, among other factors, the i mportance of the excluded e vidence to the defense, 8 Roldan argues in the a lternative t hat evidence t hat Aguas prev iously set up dr u g seiz ures is admissible under Ru le 404(b) to show Ag uas’s intent, moti ve, and plan. Ro ldan points to Unit ed States v. Abou moussa llem, in which we e xplained that eviden ce that a third party had a practice o f duping people to ac t as couriers witho ut their kno wledge would be admis sible u nder Rule 404(b) to support a defense that a third p arty likewise duped the de fendant. 726 F.2d 906, 911 – 912 (2d Cir. 1984) (“[R] isks of p rejudice are norma lly absent w hen the de fendant o ffers similar act s evidence of a third party to p rove some fact per tinent to the de fense” and, “[i ]n such cases the only issue arising under Rule 404(b) is whether the evide nce is relevant t o t he existence or non - existence of som e fact p ertinent to the defense.”). Beca use we conclud e that the evidence wa s relevant to corroborate Roldan’s testimony regarding Aguas’ s statements to him, we need not consider this alter native theory o f admissibility.

24 whether the evidence was cumulative, and the overall s trength of th e government’s case. See Unite d States v. Litvak, 808 F.3d 160, 184 (2d C ir. 2015); United States v. Oluwanisola, 605 F.3d 124, 134 (2d C ir. 2010). Of the standard considerations, the “strength of the gover nment’s case is the most crit ical factor.” United States v. McCallum, 584 F. 3d 471, 478 (2d Cir. 2009). An d w e have long recogniz ed that a n “[e] rror going ‘ to the heart ’ of a cr it ical iss ue is less likely to be harmles s.” United States v. Forreste r, 60 F.3d 52, 64– 65 (2d Cir. 1995); Unite d States v. Blum, 62 F.3d 63, 6 9 (2d Cir. 1995) (sam e). The government bears t he burden of proving that an evidentiary error w as harmless. United States v. Zhon g, 26 F.4th 536, 558 (2d Cir. 20 22). Applying these principles, we conclude that the governmen t has not carried its burden of showing that t he district court’s error w as harmless. The excluded evidence was c entral to the defen se. The main d isput e at tr ial was whether Roldan intended to participa te in a drug - traffickin g conspiracy or inste ad believed he was assis ting in a la w - enf orcement seizure. Evidence that Aguas had, in fact, prov ided information leading to successful drug seizures tended to corroborate Rold an’s testimon y as to wh at Agua s tol d hi m, and thus bore directly on the jury’s assessment of h is credibility and s tate of mind. See Detr ich, 865 F.2d at 21–22 (hold ing an evidentiary error not harmless where the exc luded ev idence

25 corroborated the defendant’s testimony o n the central issue of intent). In fact, the evidence was releva nt to Roldan’s state of min d for the same reason as the evidence of Aguas’s report to Torres about an anticipated shipmen t of drugs through the Car tagena airport— e videnc e the distr ict co urt d id ad mit. Further, the government’s case at tria l on the elem ent of intent was not overwhelmi ng. Roldan’s conduct, inclu ding his emphasis during the meetings with Vargas on the need to depos it the drugs in a warehouse b efore moving the m throu g h the airport, was a rguably consistent with an intent to part icipate in a scheme to set up a drug seizure a nd reap financial benefi ts as a resul t. And the governmen t offered no e vidence that Roldan, a low - level pa trol officer on a rural assignment, had an y experience at the Cartagena airport, conne ctions with anyone at the a irport, or the capability to pass massive quan tities of cocaine through tha t airport w ithout de tec tion. Nor was the evi dence merely c umu lativ e. It is tr ue that th e jury he ard evidence that Aguas approached Major Torre s with information about a potent ial shipment moving thr ough the airport, which tended to supp ort Roldan’s defense that his involvement in the s cheme was to set up a seizure of th e drugs before they left the country. That eviden ce, however, also es tablished th at the DEA declined to work with Aguas and instructed h im not to take independent action. As a

26 result, the admitted evidence rei nforced the government’ s narrative at trial that Aguas lacked a uthorization to conduct an undercover op eration in connection with a shipment thr ough the Cartagena airpor t. B y implic ation, this e viden ce undermine d Roldan’ s testimony that A guas told Roldan tha t he was acting with the blessing of the anti - narcotics unit. The excluded eviden ce served a distinct and critical func tion. Based on the excluded evidence, t he jury could reasonab ly have concluded that Roldan did no t actually believe he w as participating in an approve d undercover ope ration but did believe he was helpi ng to set up a CNP seizure of drugs that woul d enable him to reap a por tion of the reward mone y. The excluded evidence would have bolstered that def ense theory by supporting Rol dan’s testimony tha t Aguas reported facil itatin g seizures and securing part of t he reward money in the past. T he governm ent capitaliz ed on the evidentiary gap created by the dist rict court’s ruling. In both its pre sentation of evidence and its closing argumen t, the government emphasi zed that neither Aguas nor Roldan had ever been aut horized to conduct undercove r seizure work for the CN P. Although that asse rtion wa s factually accurate, it was mate ria lly inco mple te because it obscured the a lternative defense theo ry: that Roldan sought to set up a CNP sei zure so he cou ld benefit

27 from the reward money, e ven if he was no t conducting an a pproved undercover action. Because int ent was the central disputed issue at trial, and because the excluded evidence bore direct ly on the cre dibilit y of Roldan’s asserted understanding of the operation, there is a substantial poss ibi lity that the excluded evidence would have changed the jury ’s assessment of Roldan’s intent. Under these circumstances, we cannot conclude it is “highly probable that the error did not affect the verdic t.” Dukagjini, 326 F.3d 45 at 61. For the ab ove reasons, we VACATE the d istrict cour t’s ju dgment an d REMAND for fur ther proceedings cons istent with this opinion.