Jack, the son of a Austrian streetwalker and an American soldier, received his first life sentence at age 25 when he strangled a prostitute with her bra because she reminded him of his mother. Subsequently he admitted to the crime explaining "I envisioned my mother in front of me, and I killed her." While in jail Jack wrote a series of short stories, plays and an autobiography that made him the darling of the Viennese cafe-intellectuals. Hailed as a model for rehabilitation, Jack was granted parole in 1990.
A free man, Jack became a knight in shining armor of the Austrian literary elite. Within months of his release his success as a writer translated into expensive suits, fancy cars and regular appearances in local talk shows. However, not truly reformed, Jack did keep up with his old habit of strangling prostitutes for kicks to the tune of at least six dead.
In 1991 he was hired to write an article about prostitution in Los Angeles. While on assignment he got to travel in an LAPD patrol car. He also managed to squeeze in the murder of three prostitutes before returning back to Vienna.
By February, 1992, police in Austria issued a warrant for his arrest linking him to the deaths of eight women. By then Jack escaped with his 18-year-old girlfriend to Switzerland, Paris and New York, pausing along the way to call newspapers and talk shows in Austria to proclaim his innocence. Following a credit card trail left by the fugitive couple, they were arrested by Interpol in Miami, Florida. While in custody his girlfriend explained they sought refuge in Miami because she "liked Don Johnson."
Unterweger was eventually deported back to Austria where he was indicted for the murders of 11 prostitutes, including three from Los Angeles. On June 28, 1994 a jury in Graz, Austria, found him guilty of nine of murders and acquitted him of two others. The next morning prison guards found him dead in his cell hanging from a pyjama cord.