“American Murderer” (**1/2 out of four) was an absorbing but hollow crime melodrama based on the true story of Jason Derek Brown (Tom Pelphrey) a charismatic con man who eventually progresses to murder and becomes tracked by the FBI and one agent (Ryan Phillippe) in particular who is determined to put an end to his game for good. Two strong performances from the two leads and sturdy direction from writer/director Matthew Gentile keep you watching but somehow film is never as compelling as it should have been and never shifts into high-gear. A feature-length adaptation of Gentile’s own short film of the same name from 2019.