In the novel, Bill Turcotte lives in Derry, Maine, where he is encountered by Jake Epping when the latter travels back to 1958 to try and prevent the murder of the Dunning family. Jake gives him the nickname ‘no suspenders’ when they first meet. It turns out that Bill has a history with Frank Dunning, the murderer that Jake hopes to stop. Frank always picked on Bill, and eventually even married Bill’s sister, Clara. The two even had a son, Mikey, but one day in 1938 his wife and son disappeared. While Bill believes Frank murdered them, that was never proven. In the ensuing 20 years, Bill harbored an intense hatred against Frank but never acted on it.
When Bill finds out that Jake is planning to kill Frank because Frank is about to commit another homicide during Halloween, this time against his new wife and children, Bill attempts to stop Jake from interfering, stating he wants the honor of killing Frank himself. Jake chews Bill out for having had plenty of opportunities to do so in the past 20 years, and never doing anything. Eventually, Bill and Jake team up and manage to safe all but one of the Dunning children. Bill, a heavy smoker, suffered a heart attack shortly thereafter and was hailed by the local media as the hero who stopped the murderous Frank Dunning.
(While several reviews of 11/22/63 claim that Bill's heart attack was fatal, that never was stated in the novel.)
These events are undone, however, when Jake goes back to his own time and then travels back to 1958 again, since each trip back starts a new timeline. This time, Jake tracks down and kills Frank on Oct. 5 while he is visiting his parents' graves. He then sends Bill a letter in which he urges him to go see a doctor for his heart condition.
At the end of the story, this change is also undone by yet another time travel by Jake, and everything is restored to how it used to be. It’s unknown what became of Bill Turcotte in this original timeline.
In the miniseries, Bill Turcotte is played by George MacKay. This version of the character is noticeably younger than his book counterpart, and rather than 1958's Derry, he lives in 1960’s Kentucky, where he has a job as bartender.
Just like in the book, his sister was married to Frank Dunning and got killed by him, but Frank managed to get away with the murder since nobody believed Bill when he claimed his sister was killed. As in the book, he discovers Jake’s attempt to stop Frank from killing his current family in a drunk rage and tries to stop him, but eventually allows Jake to go ahead and stop Frank. Afterwards, Bill discovers a newspaper article about the Kennedy assassination among Jake’s belongings, and confronts him with this information. After Jake admits that he has come from the future to try and prevent the assassination, Bill becomes Jake’s ally. They move to Jodie, Texas, together, where Bill poses as Jake’s little brother. Together, they spy on Lee Harvey Oswald to find out if he acted alone in the murder on Kennedy. Bill helps Jake bug Oswald's apartment, and to spy on him.
However, once the two of them settle in Dallas, Bill falls in love with Oswald's wife Marina, Despite Jake's warnings not to interfere with Oswald's life, he begins to see her more and more often. He also starts building up a friendship with Oswald himself. When Jake finds out and confronts Bill about this, the two of them get into a heated argument that ends with Bill accidently revealing to Oswald that his appartment has been bugged, and driving Jake out of their house. Later, Jake sees how Oswald and Bill are practicing with rifles, and realizes to his horror that Bill may very well become Oswald's accomplice in the assasination of Kennedy; the hypothetical second gunman that, according to some of the conspiracy theories, truly killed Kennedy. To prevent this, Jake had Bill committed to an insane asylum.
After Jake is severely beaten up by the mob, and loses his memory, he and Sadie decide to get Bill out of the asylum again in hopes that he can help Jake remember the crucial details of his mission. Unfortunately, by this point, the shock treatments he has been subjected to have caused Bill to suffer a mental breakdown, and he is now under the impression that everything that has happened since Kentucky was just his imagination. When Jake confronts him and tells him it was all real, this becomse too much for Bill and he commits suicide by jumping out the window.