Just how Leo Humbert, who at the time of his conviction in the territory of Hawaii was a civilian, ended up as a prisoner at the Pacific Branch, U.S. Military Prison on Alcatraz Island is partially lost to the passage of time. On October 18, 1921, when Leo was received there, Alcatraz was a prison used to house, with very few exceptions, military prisoners. The men held there were broken up into two group; those in what were referred to as disciplinary companies, and those referred to as general prisoners. In the spirit of rehabilitation, the disciplinary companies were used to try to restore men who had committed relatively minor crimes to active duty. They basically served a four month period of training during which they received military-oriented instruction, more privileges than the general prisoners, the right to be referred to by name rather than number, and the ability to be evaluated at the end to go back onto active duty. The program proved rather successful in the short period of time it was in place on Alcatraz. Leo, prisoner number 13267, was not a member of this special company.
Although it is possible that the Army had intervened in some way to get him sent there, it is more likely that he was transferred there only as a stopping point on his way to McNeil Island prison in Washington, where he ultimately ended up serving the majority of his time. Leo spent about three and a half weeks as a prisoner of Alcatraz, transferring out on November 9th, so any additional punishment the Army may have hoped he would receive by being in the general prisoner population there was short-lived. No other records exist of his time there and the next mention of him is of being received at the United States Penitentiary McNeil Island, Washington on November 11, 1921.
It was a rather tense time at the prison when Leo arrived. Just a few months before, on September 5th, prisoner Roy Gardner had made good on his escape threat from McNeil, running off during a baseball game while the guards were distracted. The drama surrounding that, with Gardner recaptured in Arizona just the day before Leo arrived, had everyone at the prison on high alert. Guards were wary, procedures were tight and even the prisoners seemed to sense that screwing around was not a very good idea, especially with the count of armed guards having been increased over the last few months. Most of that increase was attributable to the fact that over seventy-five rounds had been fired at Gardner as he ran off, all of them failing to actually stop him. Things like that tended to be a little embarrassing and every guard was determined to not have a repeat performance.
None of that seemed to make the slightest difference to Leo, who was fascinated by the entire Gardner escape and constantly asked questions about it. Guards, prisoners, even the warden Thomas Maloney, none of them were exempt from questioning, with Leo spending his evenings jotting down notes in a small paper pad he kept tucked into his bed frame. He asked about which guards were on duty, who knew about it beforehand, what everyone thought had happened during Gardner’s time on the lam, and every other detail you could imagine. He also convinced a few of the prisoners to draw a map, as best as they could remember, of exactly how the caper had went down that September day. He was vocal about it too, not really bothering to hide the fact that he considered Gardner to be a hero. Eventually a few of the prisoners, possibly following some prompting from the guards, cornered Leo behind the bakery and gave a him a fairly good beating. That worked for four days, the amount of time that he was confined to the infirmary, healing up his black eyes, bleeding kidneys and other injuries. As he walked out of sickbay that day he yelled up to a guard in a tower, “I’m hoping your aim is still lousy” and then laughed before lighting a cigarette.
When he returned to his cell, the notebook of course was gone, and he found that his privilege of even having access to any kind of paper had been taken away. That did not stop Leo, it just hindered him a bit as he slowly managed to trade away cigarettes and other small items for pieces of paper and eventually an even smaller notebook than he had possessed before his beating. These items came from those prisoners who were less afraid of the guards and shared some of Leo’s thinking on the relative merits of Gardner’s escape. He continued to collect information, make maps, and keep notes during the remainder of his time at the prison. It is also likely that he managed to figure out the identity of the outside accomplice who had aided Gardner in the days immediately following his escape, something the authorities had never been able to do. That person would play a role in some of Leo’s future endeavors and may have actually been in contact with him while he was imprisoned there. Although he never actually escaped from McNeil, it is very possible that this is where the first inklings of the idea of prison escape started to form in Leo’s head.