The last time anybody heard from John Kelly Gentry Jr. was in a postcard from Southern California.
It was 1983 and the 30-year-old Michigan man had recently disappeared after his 25-year-old girlfriend, Barbara Gerber, was discovered stabbed to death at her home in Summerfield Township, Michigan, according to Reuters.
Days later, police discovered the bludgeoned body of William Veith, an Ohio man who investigators believe was also in a relationship with Gentry, Reuters reported.
Investigators eventually decided that Gentry was responsible for both killings. He has eluded police for more than three decades and now investigators believe they know, in part, how he avoided detection so successfully.
"The U.S. Marshals Service received information in the last five years that Gentry was possibly living in California as a woman, that dresses as a woman," Monroe County, Michigan, Sheriff's Detective Jeff Smith said.
Smith told the Los Angeles Times that investigators suspect Gentry began using his middle name and may have been a regular in West Hollywood at one point.
But he told Reuters there's another possible reason that would explain why Gentry's fingerprints and DNA - which remain in an FBI database - have never been flagged by authorities: He's dead.
"If he's alive he's obviously living somewhat of a law-abiding life, because otherwise the prints should come back a match," Smith said.
Authorities described Gentry as 5-feet 7-inches, and around 154 pounds, according to the Times. He is white, has brown eyes and hair, with a circular burn scar on his left elbow and the letters "LCI" burned into his upper part of the same arm, the paper reported.
According to the Times:
"Though a motive has not been officially determined, authorities speculate that Gerber and Veith learned of each other. In April 1983, Gerber was sexually assaulted, stabbed and her throat was slit. Police believe Gentry turned on her gas stove and left a burning candle nearby in hopes it would cause an explosion."
That same car later turned up in Toledo, Ohio, the same city where Veith's body was discovered in the basement of his rare coin shop, Reuters reported. His car was also missing, but was later located in South Bend, Ind.
A nationwide arrest warrant issued in 1988 for Gentry in Gerber's murder remains active, but investigators told the Times they have little to work with.
"We've tried numerous things. We've got nothing substantial to go on," Smith said.