## Facts

- The United States prosecuted Salvador De Jesus Gutierrez-Castro for illegal reentry.
- Before trial, the government sought to present two categories of expert testimony: (1) latent fingerprint identification and (2) explanation of DHS immigration databases and records.
- The government designated a fingerprint examiner (James McNutt) to opine that latent prints matched Gutierrez-Castro’s known prints using the ACE-V method.
- The defense challenged McNutt’s qualification and the reliability of ACE-V under Federal Rule of Evidence 702 and Daubert, seeking to limit or exclude expert characterization of his testimony.
- The government also designated a DHS employee (Knoll) to testify about DHS databases, record-keeping practices, and how database entries reflect immigration events relevant to proving prior unlawful presence or removal.
- The defense moved to exclude any and all expert testimony from Knoll, arguing insufficient qualifications and unreliable or unhelpful opinions.
- The court addressed these disputes through pretrial motions in limine focused on admissibility and scope of expert evidence.

## Issues

1. Whether the fingerprint examiner was qualified and whether ACE-V latent fingerprint identification testimony was sufficiently reliable and helpful to be admitted under Rule 702 and Daubert.
2. Whether the DHS employee was qualified to testify as an expert about DHS databases and record-keeping, and, if admissible, what limits were required to keep the testimony reliable, helpful, and non-prejudicial.

## Decision

- The court denied the defense request to exclude the fingerprint expert and permitted McNutt to testify as an expert in fingerprint identification.
- The court found ACE-V sufficiently reliable for Rule 702 purposes; objections concerning subjectivity, standards, and error rates affected weight rather than admissibility.
- The court denied the defense request to exclude all expert testimony from the DHS database witness.
- The court limited Knoll’s testimony to matters grounded in his DHS experience and an adequate factual foundation, and restricted testimony that would amount to unsupported speculation or legal conclusions.
- The court indicated that cross-examination, contrary evidence, and jury instructions were appropriate tools for challenging admissible but disputed expert evidence.

## Legal Principles

- Under Rule 702 and Daubert, the court must act as a gatekeeper by assessing (1) expert qualifications and (2) the reliability and helpfulness of the proposed testimony, with Rule 403 providing an additional check against undue prejudice or confusion.
- A witness may qualify as an expert based on practical experience, not only formal education, if that experience provides specialized knowledge helpful to the jury.
- Latent fingerprint identification using the ACE-V method can satisfy Daubert reliability requirements when supported by examiner training/experience, established practices, and professional standards; common critiques typically go to weight rather than admissibility.
- Expert testimony about law-enforcement or agency databases may be admitted to explain how records are created, stored, and interpreted, but should be confined to the witness’s actual expertise and should not instruct the jury on ultimate legal conclusions.

## Conclusion

The court admitted expert fingerprint identification testimony based on ACE-V and allowed expert testimony explaining DHS immigration databases and records, while cabining the database expert’s testimony to experience-based, non-speculative explanations that would assist the jury under Rules 702, Daubert, and 403.


United States v. Gutierrez-Castro, 805 F. Supp. 2d 1218 (D.N.M. 2011)