John "Cretin" Creighton was a Deputy Chief in the LAPD and the head bean counter in charge of budgeting for the department. About ten years ago he left LAPD and joined Trident Security, opening up their California branch. Their L.A. offices are located on the 59th floor of the US Bank Tower. Trident provides services for corporations and a number of wealthy individuals, including Whitney Vance. In early October 2016 Creighton talked with Harry Bosch to set up a private meeting with Vance.
After Vance died, Creighton told Bosch to "stand down." He tailed Bosch on several occasions and monitored him with drones. Creighton then came to the San Fernando Police Department to tell Bosch to discontinue any work associated with Vance. Bosch and Creighton argued, then scuffled, resulting in Bosch arresting Creighton. He was soon released and continued to monitor Bosch until the Vance estate was settled.