Terrance Tuson, 20, was taken into custody Wednesday. He's being held in the Peoria County Jail awaiting formal charges.
Tuson's arrest comes exactly one year after 20-year-old Shannon Elmore was found shot to death in a parked car. It happened near Columbia Terrace and Ellis St.
Another man is also charged in Elmore's death. Wesley Collins, 20, is awaiting trial.