Martin Dixon was Valerie's boss when she worked for LAPD.
In 2009, a police officer named Steven Mason was killed in a warehouse explosion. Ethan Ward was suspected of killing him and was arrested for it. However, shortly afterward, the investigation was abruptly dropped, leading many to believe Ethan had paid off the police.
Years later, when he was up for Chief of Police, Nicholas Turner asked Valerie and Alice to look into the case and figure out what exactly had happened, so he could make it clear that he hadn't been paid off. They learned that Steven had killed himself and his widow had shown Marty the suicide note, which he then used to blackmail her into giving him $10,000 a month through a fake charity he'd set up. Alice and Valerie uncovered this and said it was up to Nick, now guaranteed to be named Chief of Police, how to handle Marty.
He is married.
He has three children.
He works for LAPD.