## Facts

- Two runaway minors, N.K. (16) and R.O. (15), left a residential treatment facility in Scottsdale, Arizona, and soon encountered Depaul Brooks and Uawndre Fields.
- Brooks rented a hotel room and brought the minors there; the men discussed the minors’ runaway status and suggested they go to San Diego to work for Fields as prostitutes.
- R.O. told Brooks and Fields that she and N.K. were minors; the defendants nonetheless continued to house and transport them.
- Brooks and Fields introduced the minors to Julia Fonteneaux, a prostitute associated with Fields, who explained prostitution practices to the minors.
- Brooks and Fields bought the minors bus tickets to San Diego using false names, met them there, and took them to lodging.
- At Fields’s direction, online prostitution advertisements were posted for the minors; R.O. engaged in acts of prostitution while in San Diego.
- After returning to Arizona, R.O. was dropped in an area known for prostitution; police arrested her, then located and arrested Brooks and Fields based on her information.
- A jury convicted Brooks and Fields of child sex trafficking (18 U.S.C. § 1591) and interstate transportation of minors for prostitution (18 U.S.C. § 2423(a)).
- The government offered expert testimony from a law-enforcement officer experienced in child prostitution investigations regarding prostitution operations and pimp–prostitute control dynamics.

## Issues

1. Whether the district court abused its discretion under Federal Rule of Evidence 702 in admitting expert testimony about prostitution operations and pimp control methods, including psychological coercion.
2. Whether the evidence was sufficient to prove the defendants’ knowledge of the victims’ minority status (including § 1591’s “reasonable opportunity to observe” standard as applied) and intent to traffic and transport minors for prostitution.
3. Whether the district court properly applied Sentencing Guidelines enhancements, including an aggravating role enhancement as to Brooks.

## Decision

- The Ninth Circuit affirmed the convictions of Brooks and Fields on all counts.
- The court held the expert testimony was properly admitted because it assisted the jury on matters outside ordinary experience and did not improperly opine on the specific victims’ credibility or mental states.
- The court held the evidence was sufficient to support findings that defendants knew or had a reasonable opportunity to observe the victims were minors and knowingly trafficked and transported them for prostitution.
- The court vacated both sentences and remanded for resentencing due to errors in the sentencing analysis, including insufficient support and explanation for role-related enhancements.

## Legal Principles

- Expert testimony on the structure and practices of prostitution and pimp control tactics may be admitted under Rule 702 when grounded in specialized experience, helpful to the jury, and limited to general practices rather than victim-specific credibility or mental-state opinions.
- For child sex trafficking under § 1591 (as applied in this case), the knowledge element may be satisfied by proof the defendant knew the victim was under 18 or had a reasonable opportunity to observe the victim.
- Sufficiency review asks whether, viewing the evidence in the light most favorable to the prosecution, a rational jury could find each element beyond a reasonable doubt.
- Sentencing enhancements, including aggravating role adjustments, must be supported by record evidence and accompanied by findings that justify the enhancement’s level as applied to the defendant’s actual authority and conduct.

## Conclusion

The Ninth Circuit upheld convictions arising from the defendants’ recruitment, transportation, and exploitation of runaway minors for prostitution, approved the use of generalized expert testimony to explain prostitution operations and control methods, and required resentencing because the district court’s Guidelines enhancement findings were not adequately supported and explained.


United States v. Brooks, 610 F.3d 1186 (9th Cir. 2010)