Another One Goes Tonight - Peter Lovesey

"Another One Goes Tonight [is an] impeccably constructed mystery featuring the unpredictable but ever-entertaining Detective Superintendent Peter Diamond...there are plenty of red herrings to sniff out and misdirections to blindly follow. A classic whodunit."
-The New York Times Book Review

En route to investigate a late-night disturbance, a patrol car spins off the road, killing one of the cops and leaving the other in critical condition. Detective Peter Diamond is assigned to look into the case. His supervisor is desperately hoping Diamond will not discover the officers were at fault. Instead, he discovers something even worse-a civilian on a motorized tricycle was involved in the crash and has been lying on the side of the road for hours. Diamond administers CPR, but the man's fate is unclear. Soon, though, Diamond becomes suspicious of the civilian victim and begins a private inquiry that leads to a trail of uninvestigated deaths. As the man lingers on life support, Diamond wrestles with the fact that he may have saved the life of a serial killer.