Justin Lawson is the true main antagonist in Layton Brothers: Mystery Room. He is an inspector for Scotland Yard. He has a "brute-force" approach to things, and is said to be the polar opposite of Alfendi in many ways.
File 9: Good Cop, Bad Cop
In the final case of Pack 2, Justin (alongside Alfendi, Lucy and Hilda Pertinax) investigated the past murder of Keelan Makepeace and the recent murder of Keelan's daughter, Diane. It was revealed that Justin was one of Keelan's friends on the force and helped him cover up the Jigsaw Puzzle Murders. Four years prior to the beginning of Mystery Room, Justin murdered Keelan and blamed Al; he is also responsible for Al's multiple personality disorder due to hypnotising him while he was in a coma. After Diane kidnapped Al, Justin, Hilda and Lucy rushed to Forbodium Castle where Diane was going to kill Al in revenge for her father's death. For unknown reasons, Justin saved Al's life by shooting Diane dead. It was later found out that Justin had murdered 11 people of the Jigsaw Puzzle Murders.