The FBI has joined the manhunt for Justin Smith, who is accused of fatally shooting his pregnant girlfriend, Dianna Brice, dumping her body in Philadelphia, and then torching his car. The bureau released a wanted poster and said it will pay a reward for information leading to Smith’s arrest. Authorities have already made one arrest in the case: 21-year-old Tylydia Garnett is suspected of helping Smith get rid of Brice’s body and evidence and was charged with arson and abuse of a corpse. Brice, who had a 4-year-old son, was last seen with her mother at a laundromat before getting into Smith’s car. He claimed they had an argument and jumped out but then vanished himself.