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MICHAEL BAILEY 

United States Attorney 

ANNA WRIGHT

Assistant U.S. Attorney 

NATHANIEL J. WALTERS 

Assistant U.S. Attorney 

State Bar No.: 029708 

405 West Congress, Suite 4800 

Tucson, Arizona 85701-5040 

Telephone: (520) 620-7300 

E-mail: anna.wright@usdoj.gov 

 nathaniel.walters@usdoj.gov Attorneys for Plaintiff 

IN THE UNITED STATES DISTRICT COURT 

FOR THE DISTRICT OF ARIZONA 

United States of America, 

 Plaintiff, 

 vs. 

Scott Daniel Warren, 

 Defendant.

18-CR-223-TUC-RCC (DTF) 

NOTICE OF EXPERT WITNESSES 

Pursuant to the Federal Rules of Criminal Procedure, Rule 16(a)(1)(G), the United 

States, by and through undersigned counsel, provides supplemental notice of its intent to 

use expert witness testimony under Rules 702, 703, or 705 of the Federal Rules of Evidence 

during its case-in-chief at trial. 

I. Immigration and A-File Procedures Expert 

The government provides notice that it may call a prosecutions agent from the 

Border Patrol to testify regarding deportation and/or removal procedures, “A” file 

procedures, and documents contained in the A-files of the two material witnesses

apprehended in this case. Such documents include, but are not limited to, fingerprint cards, 

and deportation, and/or removal documents. The government previously provided defense 

counsel an opportunity to review the material witnesses’ A-files, and has disclosed any

relevant documents to defense counsel. Upon request and with appropriate notice, the 
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government will provide an opportunity for re-inspection of the material witnesses’ A-files. 

The documents would be used as evidence of alienage and identity.

Of note, the government called both material witnesses for video depositions and 

played both video depositions at the first trial. The defendant did not challenge their 

testimony regarding their alienage, but if the defendant contests alienage or identity at trial, 

the government may use the material witnesses’ A-files to further prove alienage. 

II. Fingerprint Expert 

Absent stipulation, the government may call a fingerprint expert from the DHS CBP 

Laboratories and Scientific Services, Southwest Regional Science Center (SWRSC), Joint 

Arizona Forensics Center, in Tucson, Arizona, to testify with regard to fingerprints taken 

from the material witnesses that will be compared to various documents in their A-files. If, 

after reviewing the A-files, the government determines a fingerprint expert is necessary, 

the government will provide a fingerprint comparison report and curriculum vitae of an 

expert to the defense. 

The government may also call a fingerprint expert from the DHS CBP Laboratories 

and Scientific Services, Southwest Regional Science Center (SWRSC), Joint Arizona 

Forensics Center, in Tucson, Arizona, to testify with regard to fingerprints taken from items 

seized from the Barn in relation to this case. 

III. Cellphone Extraction Expert 

The United States may call Border Patrol Agent Matthew Gibbs, or another 

similarly qualified agent, in its case-in-chief to testify about the cell phones seized in 

connection with the defendant’s arrest in this case. Agent Gibbs has been employed with 

the Border Patrol since 2003 and is currently an Intelligence Agent within the Border Patrol 

Digital Forensics Unit. The government will provide Agent Gibbs’ curriculum vitae to the 

defense separately. 

Pursuant to Rule 702 of the Federal Rules of Evidence, Agent Gibbs will testify at 

trial as to his technical and specialized knowledge regarding the forensic examination of 

digital devices, including cell phones. This testimony will include Agent Gibbs’ training 
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and background; the nature of his examination and analysis of the cell phones in this case; 

and the methods and software used to assist in his examination. 

Specifically, Agent Gibbs is expected to testify regarding the following subject 

areas:

1. Background information pertaining to the investigation and forensic search 

of cell phones in general. 

2. Background information about data extraction, transfer, and analysis

hardware and software aimed at acquiring both physical and logical data stored on mobile 

devices, as well as the ability to transfer the extracted data to other devices, parse acquired 

data, and analyze content. This testimony will include basic information about Cellebrite 

extraction. 

3. The basic methodology by which a technician may acquire deleted data 

during a Cellebrite physical data extraction. 

4. Basic information concerning any routine technical or administrative review 

or validation of forensic examination findings. 

5. Explanation of the Cellebrite data extraction for the source cell phone, 

including demonstrative testimony. 

6. Background information regarding Internet Evidence Finder (“IEF”), a 

digital forensics tool, and an explanation of the IEF results for the source phone data. 

7. Background information regarding WhatsApp and Kik, instant messaging 

cross-platform applications for smartphones that use the Internet to send text messages, 

images, video, user location and audio media messages. 

Additional lines of inquiry may be explored on redirect examination or rebuttal if 

the defendant opens the door. 

IV. Alien Smuggling Expert 

The government expects HSI Special Agent Michael Edwards, or another similarly 

qualified agent, to testify regarding the methods of alien smuggling in the area surrounding 

Ajo, Arizona. See United States v. Mejia-Luna, 562 F.3d 1215 (9th Cir. 2009). Special 
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Agent Edwards will testify about how aliens are guided into the United States and the 

routes aliens typically use in the area surrounding Ajo, Arizona. Special Agent Edwards 

may also testify about common obstacles aliens encounter when they illegally enter the 

United States to include law enforcement patrols, Border Patrol checkpoints, and sightings 

by civilians. Special Agent Edwards’s testimony will be based upon his training, 

experience, and education. His curriculum vitae will be disclosed separately to the 

defendant.

 Respectfully submitted this 30th day of September, 2019. 

 

 MICHAEL BAILEY 

 United States Attorney 

 District of Arizona 

 /s/Anna Wright and Nathaniel Walters

Anna Wright and Nathaniel Walters

Assistant U.S. Attorneys 

Copy of the foregoing served electronically or by 

other means this 30th day of September, 2019, to: 

All ECF Participants