Panzram later reflected on his early childhood with the sentiment that he was not liked by other children; by the age of five he claimed that he was a liar and thief, and recalled that he became meaner the older he grew.

In October 1903, Panzram's mother sent him to the Minnesota State Training School, purportedly a reform school; Panzram later wrote in his autobiography, however, that he was repeatedly beaten, tortured and raped by staff members, in a workshop the children dubbed "the paint shop" due to leaving the room "painted" with bruises and blood.

[2]: 11 [4] In January 1906, Panzram was paroled from Red Wing Training School, where he had been detained after stealing money from his mother's pocketbook.

[5][6] By his early-teens Panzram exhibited alcoholism and had a lengthy criminal rap sheet, mostly for burglary and robbery offenses.

In the coming weeks, Panzram and Benson repeatedly broke into stores and burned down buildings, especially churches, in acts of arson.

Later in 1907, after getting drunk in a saloon in Helena, Montana, Panzram enlisted in the United States Army and was assigned to the 6th Infantry at Fort William Henry Harrison.

Refusing to take orders from officers and being generally insubordinate, he was convicted of larceny for stealing $80 worth of supplies and served a prison sentence in the United States Disciplinary Barracks at Fort Leavenworth, Kansas, between 1908 and 1910, with U.S. Secretary of War William Howard Taft officially approving Panzram's sentence.

Panzram later claimed that while he had been a "rotten egg" before imprisonment at the military penitentiary, "any shred of goodness left in him was smashed out" during his time at Fort Leavenworth.

He served prison sentences both under his own name and various aliases in: Fresno, California; Rusk, Texas; The Dalles, Oregon; Harrison, Idaho; Butte, Montana; Montana State Prison; Oregon State Penitentiary; Bridgeport, Connecticut (as "John O'Leary"); Sing Sing Correctional Facility, New York; Clinton Correctional Facility, New York; and Washington, D.C., and Leavenworth, Kansas.

He was noted for his large stature and great physical strength—due to years of hard labor at Leavenworth and other prisons—which aided him in overpowering most men;[8] he also engaged in vandalism and arson.

On one occasion, he tried to sign aboard as a ship's steward on an Army transport vessel but was discharged when he reported to work intoxicated.

Panzram claimed in his autobiography that after escaping from a chain gang sentence at Rusk, Texas, he went to Ciudad Juárez, Mexico, in the winter of 1910 to try to enlist in the Federales.

Under the name "Jeff Baldwin", Panzram was sentenced to seven years in prison, to be served at the Oregon State Penitentiary in Salem, where he was taken on June 24, 1915.

Fifty-year-old Warden Harry Minto believed in harsh treatment of inmates, including beatings and isolation, among other disciplinary measures.

[8] In his prison record which noted his two aliases, "Jefferson Davis" and "Jeff Rhodes", he falsely gave his age as 30, and his place of birth as Alabama.

After two shootouts, in which he attempted to shoot Chief Deputy Sheriff Joseph Frum, Panzram was recaptured and returned to the prison.

[8] He allegedly ended up in New York City, got a Seaman Identification card and sailed on the steamship James S. Whitney to Panama.

[13] Using Taft's stolen money, Panzram bought a small sailing yacht, the Akista, and embarked on an eight-year-long murder spree which spanned several countries and involved multiple victims.

Sailing south to New York City, for three months Panzram lured sailors away from port bars onto the yacht, made them drunk before raping them and then murdered the men with Taft's stolen pistol, subsequently dumping their bodies near Execution Rocks Light in Long Island Sound.

[14] The sailor murders ended only after Akista ran aground and sank near Atlantic City, New Jersey, during which his last two potential victims escaped to parts unknown.

[16] After being released, Panzram caught a ship to southern Africa and landed in Luanda, the capital of colonial Portuguese Angola.

[7] After his return to the U.S., Panzram asserted he raped and killed two small boys,[7] beating one to death with a rock on July 18, 1922, in Salem, Massachusetts,[fn 3][18] and strangling the other later that year near New Haven.

[fn 4] After his murder spree in Salem, Panzram worked as a night watchman in Yonkers, New York, north of Manhattan, at the Abeeco Mill factory.

In Providence, Rhode Island, he stole a yawl and sailed to New Haven, seeking victims to rob and rape, and boats to steal.

Three days later, on August 29, "O'Leary" was cleared as a suspect in the stabbing death of Dorothy Kaufman of Greenburgh, committed a month prior.

[30][34][fn 5] Panzram's confession to killing a boy at Pier 28 on League island near Philadelphia in August 1928 was confirmed.

[38] Panzram later wrote that he had contemplated mass murders and other acts of mayhem, such as poisoning a city's water supply with arsenic, or scuttling a British warship in New York Harbor to provoke a war between the United States and Britain.

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.

"[8] While on death row, Panzram was befriended by an officer named Henry Philip Lesser, who would give him money to buy cigarettes.

"[46]: 118  The German horror film Schramm begins with a quote of Panzram: "Today I am dirty, but tomorrow I'll be just dirt.