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Peter McNeilly
Staff Profile

United States Attorney Peter McNeilly

Peter McNeilly is the United States Attorney for the District of Colorado. As United States Attorney, Mr. McNeilly is the chief federal law enforcement officer in the State of Colorado. He oversees all federal criminal prosecutions, as well as all civil litigation undertaken on behalf of the United States Government. He leads an office of more than 160 attorneys and professional staff members, in addition to approximately 20 government contractors.

Mr. McNeilly has been an Assistant United States Attorney in Colorado since 2014. During his time as a federal prosecutor, Mr. McNeilly has focused on pursuing members of Mexican drug cartels, combatting the deadly fentanyl epidemic, and reducing violent crime. Mr. McNeilly’s work prosecuting fentanyl cases—and particularly cases involving fatal overdoses—has made him one of the leading experts on fentanyl prosecutions in Colorado and a resource for other federal prosecutors throughout the country. As a supervisor within the U.S. Attorney’s Office, he has overseen the creation and expansion of federal task forces which focus on transnational organized crime and violent crime. Mr. McNeilly has previously served as the Deputy United States Attorney, the Chief of the Transnational Organized Crime and Money Laundering Section, the District of Colorado’s Opioid Coordinator, and the Lead Strike Force Attorney for the Denver Organized Crime Drug Enforcement Task Forces (OCDETF) Strike Force.

Mr. McNeilly is a lieutenant colonel in the United States Marine Corps. Mr. McNeilly supported commanders and advanced the rule of law as a Marine judge advocate on active duty before joining the U.S. Attorney’s Office, and he has continued that work in the reserves for his entire time with the office. On active duty, he prosecuted complex cases throughout the Marine Corps’ western region, including sexual assaults, child exploitation, financial crimes, and crimes committed in Iraq and Afghanistan. In the reserves, Mr. McNeilly has served as a prosecutor, as a legal advisor on the staff for a three-star commanding general, and he is currently in his second tour as a military judge.

Mr. McNeilly is a graduate of Pepperdine University and the law school at Indiana University—Bloomington. 

Dates of Service
2014 - Present
Updated June 17, 2025