After the Gunfight at the O.K. Corral, Behan testified at length against the Earps. He supported the Cowboys' statements that they had raised their hands and offered no resistance, and that the Earps and Doc Holliday had murdered three cowboys. After the Earps were exonerated, Deputy U.S. Marshal Virgil Earp was maimed in an ambush on December 28, 1881, and assistant deputy Morgan Earp was killed by assassins on March 18, 1882. The outlaw Cowboys named as suspects in both shootings were either let go on a technicality or were provided alibis by fellow Cowboys. Wyatt Earp killed one of the suspects, Frank Stilwell, in Tucson. Deputy U.S. Marshal Wyatt and his federal posse set out after other suspects, pursued by Behan and his county posse composed mostly of Cowboys.