Carl Panzram (June 28, 1891 - September 5, 1930) was an American serial killer who was hanged for murder. He served time under his own name and various aliases in Fresno, California; Rusk, Texas; The Dalles, Oregon; Harrison, Idaho; Butte, Montana; Montana State Reform School in Miles City; Montana State Prison (as "Jeff Davis" #4194 #3194 and "Jefferson Rhodes" #4396); Oregon State Prison ("Jefferson Baldwin" #7390); Bridgeport, Connecticut ("John O'Leary"); Sing Sing Correctional Facility, New York ("John O'Leary" #75182); Clinton Correctional Facility, New York ("John O'Leary" #75182); and Washington, D.C (Carl Panzram #33379) and Leavenworth, Kansas (Carl Panzram #31614). While incarcerated, Panzram frequently attacked guards and refused to follow their orders. The guards retaliated, subjecting him to beatings and other punishments.