According to his driver's license, Ken was born on June 24, 1974. It is mentioned that he has some prior criminal record consisting of a minor assault charge.
At an unspecified time, Ken began killing people; he would later claim he did it as a form of vigilantism. The first was a drug dealer whom he ran over with his car and stole a stash of cocaine from. After that, he began sleeping with his boss' wife, causing her husband to become abusive. Ken then killed him by pushing him down a flight of stairs and making it look like an accident. Sometime before Dex, Lies, and Videotape, Ken lost his job and his girlfriend broke up with him. His mother, who was in a retirement home, had a close encounter with petty burglar John Henry. Ken decided to take revenge on John Henry by copycatting the MO of the Bay Harbor Butcher (Dexter). His attempt to do so was sloppy and only vaguely similar to Dexter's work. Dexter used plastic restraints and surgical tools, Ken used rope and a hatchet. John escaped and told the police about what had happened. Ken was consequently arrested on suspicion, but since the authorities had no concrete evidence linking him to the crime, they had to let him go.
Later, Dexter snuck into his home and grabbed him in a rear naked choke, asking about what he had done. Ken was remorseless and admitted to his crimes, realizing that Dexter was the real Bay Harbor Butcher, and expressed his admiration for Dexter's work. Dexter then, though not having gone there with the intention to kill Ken, choked him until he passed out and brought him back to the train wagon where he had tried to kill John Henry. When Olsen awoke there, Dexter lectured him on the proper setup of a kill room and even though Olsen tried to claim he was doing the same kind of work as Dexter, Dexter chastised him for killing people for personal benefit.
Unlike most victims, Dexter purposefully left Olsen's remains for the police to find to send a message to discourage copycats.
- Unnamed drug dealer (hit with a car)
- Unnamed wife beater (pushed down a flight of stairs)
- John Henry (attempted to kill with an axe)