Margo Casselman

From prelitigation to trial and appeal, Margo Casselman litigates a range of contract and commercial disputes, business torts, constitutional and other governmental-related cases, election law cases, IP disputes, and employment-related disputes. As a member of the firm’s White Collar & Investigations practice, Margo has experience defending individuals and businesses in criminal and other government investigations at the federal and state levels. She also represents clients in arbitrations and other alternative dispute resolution proceedings. 

Margo has significant courtroom experience. Her recent courtroom successes include briefing and arguing a motion to dismiss in federal court, resulting in the grant of dismissal of claims with prejudice; cold examinations of witnesses in state and federal court during trial or preliminary injunction hearings; delivering the opening statement and examining a witness at an evidentiary hearing, resulting in the dismissal of a lawsuit; and leading a settlement conference before a U.S. magistrate judge in a federal civil rights case that ultimately settled favorably on the eve of trial. 

Prior to joining Ashurst Perkins Coie, Margo clerked for the Hon. David G. Campbell of the U.S. District Court for the District of Arizona and the Hon. Mary H. Murguia of the U.S. Court of Appeals for the Ninth Circuit. 

Margo also maintains an active pro bono practice. She has litigated Section 1983 constitutional claims to secure medical care and humane conditions for people affected by the justice system.