Clifford "Cliff" Maxwell (d. March 2007) was a former agent of the Federal Bureau of Investigation and the lover of Alicia Kent. He had been partnered with Rachel Walling for a year, and during that time they had visited the Kent's to advise them of the potential dangers associated with Dr. Kent's profession. Specifically, the FBI was concerned about the possibility that terrorists might somehow obtain radioactive material through Dr. Kent.
As a result of that meeting with the Kents, Maxwell and Alicia developed a mutual attraction that became an affair. In March 2007, the two carried out a plan to murder Dr. Kent and make it look like the work of terrorists. Maxwell was aware that a known Islamic extremist, Momar Azim Nassar, had recently been seen in the U.S. He was also aware that a controversial Islamic advocate, Ramin Samir, was living in the Silver Lake area. He manipulated evidence to throw suspicion towards these men. He parked Mrs. Kent's car in front of Samir's house and planted incriminating items in Samir's trash. He dumped the murder weapon, the radioactive material, and other items in a commercial dumpster. His efforts were ultimately not successful because the items in the dumpster were found by a scavenger. Moreover, Harry Bosch never believed the terrorism theory.
At one point when Maxwell was guarding the Kent home, Bosch and Iggy Ferras arrived to do further investigation. Maxwell attempted to block their entry to the house, but Bosch assaulted and handcuffed him. When it became clear that Maxwell was becoming a suspect, he killed Alicia so that she could not turn against him. At the same time he killed another FBI agent who was guarding Alicia. He had a shootout with Bosch, Ferras, and Rachel Walling. Maxwell shot and wounded Ferras. Ferras returned fire and seriously wounded Maxwell who fled to a shop in Grand Central Market. Realizing that he was cornered and wounded, he killed himself.