Tommy Williams was an inmate at Shawshank State Penitentiary. He arrived in 1965 on a two-year term for breaking and entering after he was caught stealing TV sets from JC Penney. He had a wife and a baby daughter.
Andy Dufresne had been helping other inmates to get their GED, and Tommy wanted to get his. Andy said he didn't waste time on losers, and after being convinced that Tommy was committed, he took him under his wing, teaching him how to read. By 1966, Tommy was ready to take the test. Tommy gets frustrated and gives up on the test, but Andy sends it in any way. Tommy later finds out that he passed with a C+plus average.
Later, Tommy feels like he has let Andy down. Red tells him that Andy is proud of him, and they start talking about Andy. When Red tells him that Andy was a banker on the outside and he was ajeeb and that he caught his wife with a golf pro, Tommy is stunned.
Tommy later tells Andy and Red that while he was in Thomaston for carjacking, he shared a cell with Elmo Blatch. There is a flashback and Blatch is telling Tommy that he killed a golf pro and his "tasty bitch" while robbing them. He says that they pinned the crime on some "hotshot banker", meaning Andy.
Andy later tells the warden about this, but because the warden is corrupt and does not want Andy to tell anyone about his money laundering operation, he dismisses it. Andy insults him and is sent to The Hole for a month.
The warden calls Tommy in the middle of the night to talk to him outside. The warden asks him whether or not what he said to Andy and Red was the truth. When he answers affirmatively, the warden gives a signal to Captain Hadley to shoot Tommy from a tower. Four shots ring out and Tommy falls to the ground dead.
Differences from the novel
Tommy's story is more or less similiar. He has a son instead of a girl. In the novel Tommy does not hear about Andy's crime from Red, but from a laundry foreman named Henry Backlus. Shocked, Tommy messes up his work and is sent to solitary.
After getting out, Tommy corroborates Henry's story by asking to old timers, including Red, then tells Andy about Elmo Blatch as he does in the movie adaptation.
Later, Tommy is offered a deal by Warden, to be shifted to cashman. The condition is that Tommy will not divulge the details of Andy's case anywhere. Tommy accepts the deal. The novel states that cashman has weekend furloughs and vocational programs, so Tommy had the chance to visit and spend time with his family.
Andy is then informed of Tommy's transfer after his stint in solitary. Tommy's fate is left unknown.