23-6107

United States v. Cristobal

UNITED STATES COURT OF APPEALS 

FOR THE SECOND CIRCUIT

SUMMARY ORDER 

RULINGS BY SUMMARY ORDER DO NOT HAVE PRECEDENTIAL EFFECT. CITATION 

TO A SUMMARY ORDER FILED ON OR AFTER JANUARY 1, 2007, IS PERMITTED AND IS 

GOVERNED BY FEDERAL RULE OF APPELLATE PROCEDURE 32.1 AND THIS COURT’S 

LOCAL RULE 32.1.1. WHEN CITING A SUMMARY ORDER IN A DOCUMENT FILED WITH 

THIS COURT, A PARTY MUST CITE EITHER THE FEDERAL APPENDIX OR AN 

ELECTRONIC DATABASE (WITH THE NOTATION “SUMMARY ORDER”). A PARTY 

CITING TO A SUMMARY ORDER MUST SERVE A COPY OF IT ON ANY PARTY NOT 

REPRESENTED BY COUNSEL. 

At a stated term of the United States Court of Appeals for the Second Circuit, 

held at the Thurgood Marshall United States Courthouse, 40 Foley Square, in the 

City of New York, on the 8th day of April, two thousand twenty-four. 

PRESENT: 

 DENNIS JACOBS, 

 RICHARD J. SULLIVAN,

 EUNICE C. LEE, 

 Circuit Judges. 

_____________________________________ 

UNITED STATES OF AMERICA, 

Appellee, 

v. No. 23-6107 

PURIFICACION CRISTOBAL, 

Defendant-Appellant.*

_____________________________________ 

*

 The Clerk of Court is respectfully directed to amend the official case caption as set forth above. 
2 

For Defendant-Appellant: JONATHAN A. ROSENBERG, 

Rosenberg Law Firm, Brooklyn, 

NY. 

For Appellee: DEREK WIKSTROM (Kyle A. 

Wirshba, Jun Xiang, David 

Abramowicz, on the brief), Assistant 

United States Attorneys, for

Damian Williams, United States 

Attorney for the Southern District 

of New York, New York, NY. 

Appeal from a judgment of the United States District Court for the Southern

District of New York (Katherine Polk Failla, Judge). 

UPON DUE CONSIDERATION, IT IS HEREBY ORDERED, 

ADJUDGED, AND DECREED that the January 25, 2023 judgment of the district 

court is AFFIRMED. 

Purificacion Cristobal, a nurse practitioner and the sole medical professional 

at a clinic in the Bronx, appeals from a judgment of conviction following a jury 

trial in which she was found guilty of one count of conspiracy to distribute 

oxycodone, in violation of 21 U.S.C. § 846, and two counts of distributing and 

possessing with intent to distribute oxycodone, in violation of 21 U.S.C. 

§§ 841(a)(1) and (b)(1)(C). Following the jury’s verdict, the district court denied 

Cristobal’s motion for a judgment of acquittal pursuant to Federal Rule of 

Criminal Procedure 29 or, in the alternative, for a new trial pursuant to Federal 
3 

Rule of Criminal Procedure 33. The district court thereafter sentenced Cristobal 

to concurrent terms of eighty-four months’ imprisonment on each of the three 

counts, to be followed by three years’ supervised release. On appeal, Cristobal 

raises a litany of challenges to her conviction and sentence, which we address in 

turn. We assume the parties’ familiarity with the underlying facts, procedural 

history, and issues on appeal. 

I. Sufficiency of the Evidence 

Cristobal first argues that the district court should have granted her motion 

for a judgment of acquittal because the government failed to prove her subjective

intent to distribute controlled substances without authorization, as is required by 

section 841. We disagree.

“We review preserved claims of insufficiency of the evidence de novo.” 

United States v. Capers, 20 F.4th 105, 113 (2d Cir. 2021) (internal quotation marks 

omitted). But even under de novo review, “defendants face a heavy burden,” 

United States v. Ho, 984 F.3d 191, 199 (2d Cir. 2020) (internal quotation marks 

omitted), because we must view the evidence “in the light most favorable to the 

government . . . credit[ing] every inference that the jury might have drawn in 

favor of the government.” United States v. Atilla, 966 F.3d 118, 128 (2d Cir. 2020) 
4 

(internal quotation marks omitted). Ultimately, “[a] judgment of acquittal is 

warranted only if the evidence that the defendant committed the crime alleged is 

nonexistent or so meager that no reasonable jury could find guilt beyond a 

reasonable doubt.” United States v. Martoma, 894 F.3d 64, 72 (2d Cir. 2017) 

(internal quotation marks omitted). 

Section 841 makes it unlawful for any person to “knowingly or 

intentionally” “distribute[] or dispense” a controlled substance “[e]xcept as 

authorized.” 21 U.S.C. § 841(a). As provided by federal regulation, licensed 

practitioners – such as Cristobal – are authorized to issue prescriptions for 

controlled substances, but only if these prescriptions are issued “for a legitimate 

medical purpose” and “in the usual course of . . . professional practice.” 21 C.F.R. 

§ 1306.04(a). In Ruan v. United States, the Supreme Court held that, when a 

defendant is authorized to prescribe controlled substances, she may not be 

convicted under section 841 unless the government “prove[s] beyond a reasonable 

doubt that the defendant knew that . . . she was acting in an unauthorized 

manner.” 597 U.S. 450, 454 (2022). 

At the same time, and as Cristobal concedes, Ruan reaffirmed that the 

government can prove the requisite knowledge “through circumstantial 
5 

evidence.” Id. at 467; see also United States v. Heras, 609 F.3d 101, 106 (2d Cir. 2010) 

(“The law has long recognized that criminal intent may be proved by 

circumstantial evidence alone.”). Moreover, to prove subjective intent, the 

government can refer to, and compare a defendant’s conduct against, “objective 

criteria such as ‘legitimate medical purpose’ and ‘usual course’ of ‘professional 

practice.’” Ruan, 597 U.S. at 467 (quoting 21 C.F.R. § 1306.04(a)). “[T]he more 

unreasonable a defendant’s asserted beliefs or misunderstandings are, especially 

as measured against objective criteria, the more likely the jury will find that the 

[g]overnment has carried its burden of proving knowledge.” Id. (alterations and 

internal quotation marks omitted). 

Against this legal backdrop, Cristobal asserts that the government failed to 

carry its burden on section 841’s intent element because the evidence 

demonstrated that she genuinely believed that she was issuing oxycodone 

prescriptions for legitimate medical reasons in the usual course of her professional 

practice. But Cristobal made these same arguments to the jury, which clearly 

rejected them. See United States v. Clarke, 979 F.3d 82, 91 (2d Cir. 2020). We must 

“defer to the jury’s determination of the weight of the evidence and the credibility 

of the witnesses, and to the jury’s choice of the competing inferences that can be 
6 

drawn from the evidence.” United States v. Landesman, 17 F.4th 298, 320 (2d Cir. 

2021) (internal quotation marks omitted). 

At trial, the jury heard ample evidence from which it reasonably could have 

concluded that Cristobal knew she was prescribing oxycodone without any 

medical purpose and outside the course of professional practice. For example, 

multiple witnesses testified to telling Cristobal that her patients were selling or 

abusing the drugs she prescribed. Christian Ohaeri, a cooperating coconspirator 

and pharmacist who often filled prescriptions written by Cristobal, testified to 

warning Cristobal in October 2019 that the majority of her patients were selling 

the drugs she was prescribing. Destiny White and Daniella LoCicero, whom 

Cristobal hired as receptionists after first treating them as patients, likewise 

testified that the clinic was regularly filled with visibly high patients waiting to 

receive their prescriptions. Indeed, White testified that she repeatedly informed 

Cristobal that these waiting patients appeared to be high; she also pressed 

Cristobal to set up a drug testing program to confirm that oxycodone patients were

not selling their prescribed drugs or taking unprescribed narcotics. Despite these 

warnings, the evidence reflected that Cristobal continued in her prescribing 

practices. 
7 

The government also introduced evidence that Cristobal dramatically 

deviated from the ordinary practices of other medical providers, offering 

circumstantial support of her intent to act without authorization. See Ruan, 597 

U.S. at 467. This evidence reflected that, among other things, Cristobal allowed 

her patients to choose between narcotics according to their preference and 

regularly issued prescriptions without conducting physical examinations (and, in

fact, lacked the medical equipment necessary to perform them). In addition, 

Cristobal routinely prescribed a combination of oxycodone, Xanax, and Adderall

– a rarely prescribed trifecta of drugs that each treat different conditions and are 

dangerous to take together, but when used in combination, produce an intense

high and, as a result, have high combined street values. Expert testimony 

established that these practices represented deviations from the usual course of 

professional practice. 

Other unusual circumstances that supported a finding of subjective intent

included Cristobal’s practice of charging clients, who often paid in cash, by the 

prescription; her withholding of prescriptions based on patients’ inability to pay; 

and her instructions that patients avoid filling prescriptions at large pharmacies 

where oxycodone prescriptions were more likely to be closely scrutinized. 
8 

Cristobal also required her patients to sign forms in which they promised not to 

disclose any information about Cristobal to law enforcement and which warned 

that doing so “w[ould] be deemed and construed as entrapment.” Suppl. App’x 

at 91–92. 

Based on this considerable evidence, there is no question that a reasonable 

jury could have found beyond a reasonable doubt that Cristobal knew that she 

was unlawfully prescribing oxycodone. See United States v. Moore, 423 U.S. 122, 

142–43 (1975) (affirming sufficiency of evidence where the defendant gave patients 

“inadequate physical examinations or none at all,” “ignored the results of the tests 

he did make,” “took no precautions against . . . misuse and diversion,” “did not 

regulate the dosage at all, prescribing as much and as frequently as the patient 

demanded,” and charged by the “number of tablets desired” instead of “for 

medical services rendered”); see also United States v. Maye, 649 F. App’x 15, 16 (2d 

Cir. 2016) (affirming sufficiency of evidence based on “ample circumstantial 

evidence,” including expert testimony about the “usual course of medical 

practice” and evidence that defendant failed to conduct patient examinations or 

obtain medical records). 
9 

II. Expert Testimony

Cristobal also contends that the district court erred by permitting the 

government’s expert witness, Dr. Christopher Gharibo, to offer legal conclusions

regarding the standards of care that applied to doctors prescribing controlled 

substances in New York. We review a district court’s decision to admit evidence, 

including expert testimony, for abuse of discretion.1 United States v. Romano, 794 

F.3d 317, 330 (2d Cir. 2015). A district court abuses its discretion when its decision 

“rests on an error of law” or “clearly erroneous factual finding,” or when the 

decision “cannot be located within the range of permissible decisions.” United 

States v. Kaplan, 490 F.3d 110, 118 (2d Cir. 2007) (internal quotation marks omitted). 

We cannot agree that Dr. Ghabiro provided an impermissible legal 

conclusion when he testified that regulations in New York state require 

practitioners to conduct physical examinations before prescribing oxycodone. 

While Cristobal is correct that “[a]s a general rule,” “an expert’s testimony on 

issues of law is inadmiss[i]ble,” we have allowed experts to testify on relevant

regulations and industry standards as a basis to evaluate a defendant’s conduct

and intent. United States v. Bilzerian, 926 F.2d 1285, 1294 (2d Cir. 1991); see also

1 For the purposes of this order, we assume – without deciding – that Cristobal’s counsel lodged 

a timely objection at trial to the admission of this expert testimony.
10 

United States v. McElroy, 910 F.2d 1016, 1023–24 (2d Cir. 1990). And as Ruan makes 

clear, evidence as to the “‘usual course’ of ‘professional practice’” – when 

considered in conjunction with the defendant’s conduct – is relevant to the jury’s 

evaluation of the defendant’s subjective intent. See Ruan, 597 U.S. at 467. 

Here, Dr. Gharibo testified that practitioners acting in the usual course of 

professional practice conduct physical examinations before prescribing 

oxycodone, and cited a New York state regulatory requirement. In doing so, Dr. 

Gharibo did not “suggest to the jury that it could find [Cristobal] guilty simply by 

reason of [her] violation of the regulation,” McElroy, 910 F.2d at 1023, nor did he 

express any opinion as to Cristobal’s own state of mind, see United States v. 

DiDomenico, 985 F.2d 1159, 1164 (2d Cir. 1993). Accordingly, we cannot say that 

the district court abused its discretion in allowing this evidence.2

III. Jury Instructions 

Next, Cristobal contends that the district court erroneously instructed the 

jury to apply an objective, rather than subjective, standard of intent in violation of 

2 Cristobal asserts, on reply, that Dr. Gharibo was not qualified as an expert to offer testimony on 

the “New York regulatory requirements governing psychiatric practitioners” like herself. Reply 

Br. at 1–2. Because she did not make this argument in her principal brief, we deem it forfeited 

and do not address it here. See JP Morgan Chase Bank v. Altos Hornos de Mexico, S.A. de C.V., 412 

F.3d 418, 428 (2d Cir. 2005) (“[A]rguments not made in an appellant’s opening brief are [forfeited] 

even if the appellant pursued those arguments in the district court or raised them in a reply.”). 
11 

Ruan. Although Cristobal proposed her own jury charge on the requisite intent, 

she did not object to the district court’s proposed instruction at the charge 

conference. Accordingly, we review this challenge for plain error. See United 

States v. Crowley, 318 F.3d 401, 412–14 (2d Cir. 2003). To prevail on plain-error 

review, an appellant must demonstrate that the error “is clear or obvious,” 

“affected the appellant’s substantial rights,” and “seriously affects the fairness, 

integrity[,] or public reputation of judicial proceedings.” United States v. 

McCrimon, 788 F.3d 75, 78 (2d Cir. 2015) (internal quotation marks omitted). 

In charging the jury on the element of intent, the district court instructed 

that the government must prove that Cristobal “distributed or dispensed, or 

caused to be distributed or dispensed, oxycodone knowing or intending that the

prescription was not issued for a legitimate medical purpose by an individual

practitioner acting in the usual course of her professional practice.” Suppl. App’x 

at 224 (emphasis added). The district court went on to define the terms 

“legitimate medical purpose” and “usual course of professional practice” to mean 

“acting in accordance with a standard of medical practice generally recognized 

and accepted in the State of New York.” Id. 
12 

Contrary to Cristobal’s assertions, this instruction comports with Ruan’s 

requirements. As noted above, a practitioner violates section 841 when she

knowingly issues prescriptions in an unauthorized manner. And, as the Ruan

Court recognized, the scope of a practitioner’s prescribing authority is defined by 

federal regulation with “reference to objective criteria such as ‘legitimate medical 

purpose’ and ‘usual course’ of ‘professional practice.’” 597 U.S. at 467 (quoting 

21 C.F.R. § 1306.04(a)). We find no error, let alone plain error, in the district 

court’s instructions discussing these objective criteria by reference to the medical 

practice standards of New York, the state in which Cristobal was licensed to 

practice.

More fundamentally, the district court did not incorrectly transform the 

subjective intent standard into an objective one. To the contrary, the district court 

repeatedly told the jury that the government had to prove not just that Cristobal 

acted without a legitimate medical purpose, but that she knew she was doing so. 

See Suppl. App’x at 220–27; Ruan, 597 U.S. at 457–61; see also United States v. Al 

Kassar, 660 F.3d 108, 127 (2d Cir. 2011) (“[W]e examine not only the specific 

language that the defendant challenges but also the instructions as a whole to see 

if the entire charge delivered a correct interpretation of the law.” (internal 
13 

quotation marks omitted)). Because the district court correctly instructed the jury 

that it must find Cristobal’s subjective consciousness of guilt in order to convict, 

her challenge to the jury instruction fails.

IV. Brady Violations 

Cristobal also asserts that a new trial is warranted because the government 

violated its obligations under Brady v. Maryland, 373 U.S. 83 (1963), in two distinct 

ways. First, she contends that the government did not timely disclose 

information that could have been used to impeach Ohaeri — namely, his guilty 

plea to fraud involving the writing of fake prescriptions in Cristobal’s name and a 

packet of information containing all prescriptions that he wrote in her name. 

Second, Cristobal argues that the government waited until mid-trial to disclose 

that the hard-copy patient files seized from Cristobal’s clinic had been

incompletely scanned, so that the electronic productions of those files previously 

made by the government did not accurately reflect their full contents. After 

discovering the scanning error mid-trial, the government reviewed the hard-copy 

files and promptly produced electronic versions of 143 additional pages, taken

from 95 of Cristobal’s 612 patient files, which had not previously been digitized or 

shared electronically with defense counsel.
14 

To establish a Brady violation, “a defendant must show that: (1) the 

[g]overnment, either willfully or inadvertently, suppressed evidence; (2) the 

evidence at issue is favorable to the defendant; and (3) the failure to disclose this 

evidence resulted in prejudice.” United States v. Coppa, 267 F.3d 132, 140 (2d Cir. 

2001); see id. at 135 (explaining that “favorable evidence” refers to both exculpatory 

and impeachment evidence). Because Cristobal raised these claims in her motion 

for a new trial under Rule 33, we review the district court’s denial of that motion 

for abuse of discretion. See United States v. Hunter, 32 F.4th 22, 30 (2d Cir. 2022). 

As to her first Brady claim, Cristobal has failed to show that the government 

suppressed impeachment material relating to Ohaeri. For starters, the record 

reflects that materials regarding Ohaeri’s cooperation and guilty plea were 

disclosed in real time as they were generated or shortly thereafter. Moreover, as 

the government explains (and Cristobal does not dispute), the packet of 

information that Cristobal describes consisted of additional information regarding 

Ohaeri’s prescription-filling history that defense counsel requested after the start 

of trial, which the government did not possess at the time but obtained from 

Ohaeri’s counsel and immediately disclosed. The government had no obligation 

to discover and collect materials that it did not possess. See United States v. 
15 

Avellino, 136 F.3d 249, 255 (2d Cir. 1998) (limiting Brady to evidence “that is known 

to the prosecutor”); see also United States v. Hutcher, 622 F.2d 1083, 1088 (2d Cir. 

1980) (“Clearly the government cannot be required to produce that which it does 

not control and never possessed or inspected.” (internal quotation marks 

omitted)). In any case, even assuming that these materials were suppressed, 

Cristobal does not meaningfully explain how they were favorable to her, or how 

any belated disclosure of the materials resulted in prejudice. See Coppa, 267 F.3d 

at 140; see also id. at 142 (“[W]e have never interpreted due process of law as 

requiring more than that Brady material must be disclosed in time for its effective 

use at trial.”). 

Cristobal’s second Brady claim – pertaining to the improperly scanned 

patient files – is also unavailing. As Cristobal acknowledged and as the district 

court found, the physical files underlying this Brady claim were available for 

defense counsel’s review for more than a year prior to the start of trial. And 

again, Cristobal does not explain how these files were favorable to her case. She 

does not identify any pages, individually or in the aggregate, that she would have 

used at trial, nor does she assert that the government relied on the inclusion or 

omission of these pages to her detriment. See United States v. Montague, 67 F.4th 
16 

520, 538–39 (2d Cir. 2023) (rejecting Brady claim where defendant “d[id] not show 

that the record was favorable to him because it was exculpatory or impeaching” 

(alterations and internal quotation marks omitted)). Moreover, Cristobal fails to 

meaningfully articulate how the belated disclosure of these pages gives rise to a 

“reasonable probability” that the outcome of the case was affected. See Coppa, 267 

F.3d at 135, 143. She omits mention of the steps taken during trial to mitigate any 

prejudice from the mid-trial disclosure; the government, for example, refrained 

from using any of the previously unscanned documents in its case-in-chief, unless 

such inclusion would be favorable to Cristobal. 

Accordingly, the district court did not abuse its discretion in determining 

that the government’s mid-trial disclosure did not warrant a new trial in this case. 

V. Drug Quantity Calculation 

Finally, Cristobal argues that the district court impermissibly speculated as 

to the total number of her unlawful oxycodone prescriptions when it calculated 

her base offense level under the Sentencing Guidelines. We review the 

procedural reasonableness of a sentence “under a deferential abuse-of-discretion 

standard,” United States v. Yilmaz, 910 F.3d 686, 688 (2d Cir. 2018), and have held 

that a “district court errs procedurally when it fails to calculate (or improperly 
17 

calculates) the Sentencing Guidelines range,” United States v. Alvarado, 720 F.3d 

153, 157 (2d Cir. 2013) (internal quotation marks omitted). At sentencing, the 

government bears the burden of proving drug quantity by a preponderance of the 

evidence, see United States v. Colon, 961 F.2d 41, 43 (2d Cir. 1992), and we review 

the district court’s drug-quantity calculation for clear error, see United States v. 

Jones, 531 F.3d 163, 176 (2d Cir. 2008). 

Cristobal contends that the district court improperly assumed, based on her 

convictions for unlawful distribution of oxycodone on two occasions, that some or 

all of the prescriptions she issued in 2019 and 2020 were unlawful. But in fact, the 

district court took the opposite approach. In reaching its drug quantity 

calculation, the district court examined “specific evidence” introduced at trial, 

including “drug records” in the form of prescription data and “live testimony” 

from numerous coconspirators about Cristobal’s prescribing practices. See United 

States v. Shonubi, 103 F.3d 1085, 1089–92 (2d Cir. 1997); see also United States v. 

Blount, 291 F.3d 201, 215 (2d Cir. 2002) (“In making [a drug quantity] estimate, the 

court has broad discretion to consider all relevant information.”). For example, 

the district court considered that approximately half of Cristobal’s patients who 

received oxycodone prescriptions had no MRIs or other clinical documentation to 
18 

substantiate their prescriptions, and that the percentage of Cristobal’s oxycodone 

prescriptions significantly increased during the relevant period, while 

prescriptions for controlled substances outside of the oxycodone-Xanax-Adderall 

combination significantly decreased. 

In the end, the district court adopted a conservative approach and found

only one third of Cristobal’s prescriptions to be unlawful, despite expressly 

recognizing that the evidence supported such a finding as to all prescriptions

identified by the government. Based on the record, we cannot conclude that the 

district court’s calculation was clearly erroneous. 

* * * 

We have considered Cristobal’s remaining arguments and find them to be 

without merit. Accordingly, we AFFIRM the judgment of the district court.

FOR THE COURT: 

Catherine O’Hagan Wolfe, Clerk of Court