Unreported / Non-Citable
Background
Miguel Rolon was convicted after a jury trial in the Southern District of California of two counts of bringing a noncitizen to the United States for financial gain under 8 U.S.C. § 1324(a)(2)(B)(ii), and one count of conspiracy to bring a noncitizen to the United States for financial gain under 18 U.S.C. § 371. On appeal he argued only that the district court abused its discretion in admitting expert testimony from Customs and Border Protection Officer Alexander Medina. The Ninth Circuit resolved the case in an unpublished memorandum disposition, which is not precedent except as provided by Ninth Circuit Rule 36-3.
Medina had eight years of experience as a CBP officer and had been involved in more than 60 alien smuggling investigations. He had also reviewed phones used by people charged with alien smuggling, listened to jail calls involving such people, and was fluent in Spanish. His testimony concerned the term "pollos," which mattered because Rolon had said that "the pollos are snitching on me." Rolon raised two challenges. First, the district court made no explicit reliability finding on the record before admitting the testimony. Second, the government's Rule 16 notice allegedly omitted a list of other cases in which Medina had testified in the prior four years. The trial record also included testimony from one of Rolon's undocumented passengers and video of his border entry and post-arrest interview.
The Court’s Holding
The panel affirmed. It reviewed the admission of expert testimony for abuse of discretion and would reverse for an abuse only if the error was not harmless. The panel assumed, without deciding, that the district court was obligated to make an explicit reliability finding on the record. Any failure to do so was harmless because Medina's testimony was reliable and rested on relevant experience and knowledge. Citing Mendoza-Paz, the panel noted that in the law enforcement context reliability depends heavily on the expert's knowledge and experience rather than on methodology or theory.
The panel also concluded that the jury more likely than not would have reached the same verdict without Medina's testimony. The trial featured what the panel called overwhelming evidence of guilt: Rolon's changing stories, logical inconsistencies between his statements and other evidence, a passenger's testimony, and the border-entry and interview video. The jury did not need the word "pollos" explained to infer that Rolon's remark that the pollos were snitching on him showed he was not an unknowing driver doing a favor for a friend.
On the Rule 16 claim, the panel assumed the government's notice was insufficient for omitting the list of Medina's prior testimony, but found no prejudice. The standard asks whether the verdict likely would have been different had the government complied with the discovery rules, not whether the evidence would have been suppressed. It was unclear how Rolon would have questioned Medina differently, and given the volume of other evidence the panel found it highly unlikely the verdict would have changed. The panel also granted Rolon's unopposed motion to supplement the record.
Key Takeaways
- A court of appeals may assume a district court should have made an explicit Daubert reliability finding and still affirm if the record shows the testimony was reliable and any error was harmless.
- For law enforcement experts, reliability depends heavily on knowledge and experience rather than scientific methodology, so years of investigative work and language fluency can support the foundation.
- An error in admitting expert testimony is harmless when the jury more likely than not would have reached the same verdict without it.
- A Rule 16 disclosure defect warrants reversal only if the defendant shows a likelihood that the verdict would have been different had the government complied.
- A defendant who cannot explain how he would have cross-examined an expert differently will struggle to show prejudice from an incomplete expert notice.
Why It Matters
Although it is nonprecedential, the memorandum shows how the Ninth Circuit handles challenges to officer-expert testimony in alien smuggling prosecutions. It looks to the officer's practical experience and then asks whether the verdict would have differed without the testimony. Because the panel assumed error on both issues, it did not decide whether a district court must make explicit reliability findings on the record, or whether the government's notice actually violated Rule 16.
Those questions remain open for future cases. Defendants raising similar claims should be prepared to show concretely how the missing disclosure would have changed cross-examination, and how the remaining evidence leaves room for a different verdict. Rolon's convictions stand.