In the original timeline, Wes Gilliam was the son of bartender Joel Bender and flight attendant Claire Gilliam. Wes was conceived during a one night stand between the couple at the Toledo Express Inn. When Wes grew up, he murdered two women and was sentenced to life imprisonment.
In the altered timeline, Garcia Flynn tells Wyatt Logan that Wes was the killer of his wife, Jessica Logan, after his cooperation with a scheme to capture Benedict Arnold. Later, Rufus Carlin and Wyatt steal the Lifeboat, to travel to March 19, 1983, to try and prevent Claire and Joel from conceiving to prevent the murder of Jessica. The conception of Wes is prevented, but results in the accidental death of Joel. When Rufus and Wyatt return, the two women Wes murdered in the original timeline are alive, but Jessica is still dead.
After Flynn kills Jessica to save Rufus Carlin, Wyatt realizes that Flynn lied about Wes being the killer though he realizes that Flynn had been trying to save his life instead of ruin it as Wyatt originally believed.