An Illinois native, he briefly operated a successful private practice in LaSalle until his addiction to alcohol drove most of his business away.

[9] 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.

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.

In March 1933, Moran performed plastic surgery on gang members Fred Barker and Alvin Karpis for a fee of $1,250 (equivalent to $29,000 in 2023).

[4] When the Barker-Karpis Gang kidnapped and ransomed Minnesota banker Edward Bremer for $200,000 (equivalent to $4,555,000 in 2023), Moran helped launder the money through his practice in Chicago.

[11] 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.

[12] The most accepted version of the tale is that Karpis, along with Fred Barker, took Moran on a boat ride on Lake Erie, during which they both murdered him.