During World War I, Moran served as a pilot in the Army Signal Corps with the rank of lieutenant. Moran graduated from Tufts Medical School, Boston. An Illinois native, he briefly operated a successful private practice in LaSalle until his addiction to alcohol drove most of his business away. To maintain his income, Moran became what was then colloquially known as a "pin artist". In 1928 he was eventually caught, convicted and sentenced to prison after one of his patients died. He received a ten-year jail term, and lost his medical license. While in prison he ran the prison hospital successfully. The warden, Henry C. Hill, was so impressed that he helped him to obtain parole in 1931 and secured the return of his medical license. After his release, he moved to Bureau, Illinois. He was suspected of further abortions and was returned to prison, serving another 11 months for violating his parole.
Apparently embittered by what he considered to be an unfair re-internment, Moran cultivated links with gangsters, facilitated by his friendship with jewel thief Oliver Berg, whom he had treated in LaSalle jail. Berg helped him make contacts in the Chicago underworld, and he was appointed the official physician of the Chicago Teamsters, Chauffeurs, Warehousemen and Helpers Union. Unofficially, he became the emergency care physician for much of the Chicago underworld, despite being fairly debilitated by alcoholism. He set up his business on Irving Park Boulevard. Mostly he stitched cuts and removed bullets from wounded gangsters such as Dillinger-gang member John "Red" Hamilton, from whom he removed five bullets after one robbery. However, in 1934 Moran began touting his skills as a plastic surgeon, able to change the faces and fingerprints of notorious outlaws in order to hinder police identification.
It was in this capacity that he became associated with the Barker-Karpis Gang. In March 1933, Moran performed plastic surgery on gang members Fred Barker and Alvin Karpis for a fee of $1,250. He was successful in removing Karpis' fingerprints, but his work on the two men's faces was judged a dismal and painful failure. When the Barker-Karpis Gang kidnapped and ransomed Minnesota banker Edward Bremer for $200,000, Moran helped launder the money through his practice in Chicago. Six months later, while drinking with the gang in a club just outside Toledo, Ohio, Moran drunkenly bragged about the power he now held over the gang, knowing the incriminating details about their crime, saying, "I have you guys in the palm of my hand." It is this assertion that is believed to have sealed his fate.
Death
Moran was not seen alive again after the drunken bragging incident in July 1934. On September 26, 1935, a badly decomposed body washed up on the shores of Crystal Beach, Ontario, without its hands and feet. The FBI subsequently identified the body as Moran's by means of dental records. In 1971, Alvin Karpis wrote in his autobiography that the identification was mistaken; he claimed that Moran had been murdered by Arthur and Fred Barker and then buried in a lime pit in Michigan. The most accepted version of the tale is that Karpis himself, along with Fred Barker, took Moran on a boat "ride" on Lake Erie, during which they both murdered him.
In other media
Joseph Moran appears as a character in the Stephen Kingshort story "The Death of Jack Hamilton".
Dr. Herman Einstein, the drunken, incompetent criminal plastic surgeon in Arsenic and Old Lace is loosely based on Joseph Moran.
The drunken "Doc Saunders" in the 1957 filmBaby Face Nelson is based on Moran. In this version he is killed by Nelson and dumped in the lake after failing to successfully alter Nelson's fingerprints.
Corrupt mob-doctor "Dr. Guelffe" in Guns Don't Argue and Ma Barker's Killer Brood is based on Moran.