Who is Philip Glass from Chasing the Dime: A Novel and what is their importance?

Philip is a private investigator with an office in Culver City. He was contacted by Mrs. Quinlan and hired in an effort to find her daughter. He is clean shaven and has deeply set, dark and hard eyes. He is in his thirties and favors jeans and t-shirt. He is a cautious man, and knows a great deal about the business dealings of Billy Wentz, and has a deep fear of involvement with him. He specialty is missing persons, and he was recommended to Vivian Quinlan by someone in LAPD's missing persons unit.