Fate's Shadow. The Xander Drew Series, #5

Thomas Horton was a good cop. Focused and unyielding, he had one of the highest solved-case rates in Los Angeles, a city with the highest unsolved murder rate in the whole of the United States. He has been murdered. On his last case he had worked with a driven, obsessive young vigilante named Xander Drew. That association had cost him his career, and now may get that same case thrown out of court without his testimony to defend it.
In order to find the killer and protect the outcome of the case, FBI Agent Duncan Taggart must once again enlist in Xander's help, dragging him out of his self-imposed exile at the same time. Things become even more complicated when star attorney Megan Greene is hired to handle the case, bringing Xander into conflict with an ally from his youth in Maine. Can Xander overcome the remnants of his past and put Horton's memory to rest? Or will his impulses make an already dangerous case even more so?