Biography
Frank Ambrose was an Earth Liberation Front activist and the then-husband of fellow ELF organizer Marius Mason. He participated in numerous Indiana and Michigan ELF actions between 1999 and 2003, including tree-spikings and arsons of homes under construction. After federal investigators tied him to the actions in 2007, he agreed to cooperate with prosecutors and over the following year recorded approximately 178 conversations with Marius Mason and other activists for the FBI. His testimony was the principal basis for the 22-year sentence Mason received in February 2009 — at the time the longest sentence ever imposed on a U.S. eco-defendant.
Ambrose divorced Mason on the day of Mason's arrest. He pleaded guilty to conspiracy to commit arson and was sentenced in October 2008 by U.S. District Judge Paul Maloney to 9 years in federal prison; that sentence was later reduced by the same judge to less than six years in light of his cooperation. He served his sentence at federal facilities and has not been publicly active since release. He is widely regarded within the radical-ecology movement as the most consequential federal informant of the Green Scare era; he is included here because he served meaningful federal prison time.
