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Peter Lacny was born in DuBois, Pennsylvania in 1979. He was admitted to the Montana State Bar in 2006, the U.S. District Court in 2006, the Ninth Circuit Court of Appeals in 2008 and the United States Supreme Court in 2013.

Practice Areas

Peter is a partner at Datsopoulos, MacDonald & Lind, P.C. Peter has obtained acquittals for accused clients in both state and federal courts. He has handled appeals to the Montana and United States Supreme Courts, and has argued in front of the Ninth Circuit Court of Appeals.

Peter’s practice areas include white collar criminal defense, general criminal defense, personal injury law and general civil litigation.

In addition to his court room work, Peter has represented numerous professionals—including attorneys, nurses, doctors and law enforcement— facing disciplinary action from their licensing boards.

Peter has also represented numerous college students facing expulsion for violating university student conduct codes.

Peter is a proud and active member of the District of Montana’s federal Criminal Justice Act Panel. During law school, he was trained at and tried cases for the Colorado Public Defender’s Office and worked in the law school’s criminal defense clinic.

Peter is recognized statewide as an expert in federal and state firearm laws, on which he regularly lectures and consults with other attorneys.

Memberships and Activities

Vice President, Montana Association of Criminal Defense Lawyers

Member, National Association of Criminal Defense Lawyers

Member, Montana Trial Lawyers Association

Member, Federal Bar Association


Montana State University (B.A., History, 2002); University of Montana School of Law (J.D. With Honors, 2006).


Super Lawyers (Rising Stars) 2013, 2014, 2015

ACLU’s 2007 Vern Klingman award for work in securing pardons for Montanans convicted under the sedition act.

Speaking Engagements

The Other Evidence Rules: CLE instructor at 2013 State Bar Criminal Law Section conference in Missoula, MT. Lecture focused on state evidence rules.

Contemporary Issues in Civil and Criminal Practice: CLE Instructor at 2012 Fall MTLA conference in Missoula, MT. Lecture focused on intersection between civil and criminal practice.

Out of My Cold Dead Hands: CLE instructor at 2010 Montana Criminal Defense Lawyers Annual Seminar in Chico, MT.  Lecture focused on federal firearms law.

University of Montana School of Law:  Peter has guest lectured at the University of Montana School of Law on a variety of topics.