Joseph Driscoll may not be his real name as Dexter found no records of his early life.
According to Dr. Pittman, Joe was in the U.S. Army and served in the Vietnam War, although there is no proof of this. (Dexter told Dr. Pittman that Joe spent some time in prison because of his tattoo.)
In 1976, Joe settled in Dade City, Florida, after buying his house outright with cash. Before that, they are no records of his life, or any childhood photos. His life appeared to start when he was 30-years-old. Dexter speculated that Joe spent in prison, mixed with some bad people and had to hide from them.
While staying at his house, Dexter learned that Joe was an expert bowler and had recovered from drug abuse.
At the age of 60, Joe met his demise when Brian Moser (under the alias of Rudy Cooper) schemed to reconnect with his long-lost brother, Dexter. He tracked Joe down and accessed his house while disguised as a cable repairman. Brian slipped Joe a sedative and injected him with diabetic insulin, which caused Joe to have a seizure and die of cardiac arrest.
Dexter is notified of Joe's death, becomes executor-of-his-will, and inherits his house and possessions. Dexter initially thinks it's some some sort of mistake because he believes that his bio dad died when he was a child.
Dexter and Rita drive to Dade City to sort out Joe's house and sell it. Once there, Deb and Rudy show up unexpectedly to help them.
The next morning, Dexter goes to the morgue to meet with Dr. Pittman who rolls out Joe's body. Dexter denies that Joe is his father, until he recognizes the spider-web tattoo on his right elbow. A memory surfaces from his past.
(Flashback) Dexter is young and, having injured himself, is in the hospital after. He needs surgery but he has a rare blood type. Harry, his adoptive father, knows someone who has the same blood type and the person provides a transfusion. Afterward, Dexter draws a handmade thank-you-card for the man, and Harry promises to make sure he gets it. (The man, who turns out to be Joe, apparently treasured the card as he kept it through the years.)
Dexter secretly takes blood samples of himself and Joe and sends them to Vince Masuka to perform a DNA test. It comes back a match which surprises Dexter and upsets Debra.
Dexter suspects that Joe's apparent heart attack was actually murder. However, the body is cremated before Dexter can obtain proof. As such, he never discovers Rudy's involvement.
During the night, Dexter breaks into the morgue and steals Joe's ashes. Rudy picks him up and convinces him not to throw them away. Joe is then laid to rest by Dexter (accompanied by Rudy) at the entrance of Joe's favorite bowling alley where he scatters the ashes.
- Brian Moser visited Joe dressed as a cable repairman most likely to avoid suspicion from the neighbors (e.g., Irma Holt).
- Joe and Dexter share a physical resemblance; also, both are skillful bowlers.