In light of his extensive criminal record, Panzram was sentenced to 25-years-to-life. Upon arriving at Leavenworth Federal Penitentiary, identified as inmate #31614, he warned the warden, "I'll kill the first man that bothers me". Because he was considered too psychotic he was assigned to work alone in the prison laundry room, where the foreman, Robert Warnke, was known to bully and harass other prisoners under him. Warnke soon antagonized Panzram, despite the latter repeatedly warning him to back off. On June 20, 1929, Panzram beat Warnke to death with an iron bar. He was convicted and sentenced to death. He refused to allow any appeals of his sentence. In response to offers from death penalty opponents and human rights activists to intervene, he wrote, "The only thanks you and your kind will ever get from me for your efforts on my behalf is that I wish you all had one neck and that I had my hands on it." While on death row, Panzram was befriended by an officer named Henry Philip Lesser, who would give him money to buy cigarettes. Panzram was so astonished by this act of kindness that, after Lesser provided him with writing materials, Panzram wrote a detailed summary of his crimes and nihilistic philosophy while awaiting execution. Panzram explicitly denied having any remorse for any of his actions and began his journal with the statement that, "In my lifetime I have murdered 21 human beings, I have committed thousands of burglaries, robberies, larcenies, arsons and, last but not least, I have committed sodomy on more than 1,000 male human beings. For all these things I am not in the least bit sorry." Panzram was hanged on September 5, 1930. As officers attempted to place a customary black hood over his head, he spat in the executioner's face. When asked for any last words, he responded, "Yes. Hurry it up, you Hoosier bastard; I could kill a dozen men while you're screwing around!" He was buried in the Leavenworth Penitentiary Cemetery, where his grave is marked only with his prison number, 31614. Legacy In 1938, Karl Menninger wrote Man Against Himself. He included material about Panzram, referring to him as using the pen name of "John Smith," and identified him as prisoner No. 31614. Former prison guard Henry Lesser preserved Panzram's letters and autobiographical manuscript. He spent the next four decades trying to have this material