Mistaken Identity

My book takes place in Bangor, ME after WWII. It is a story about a group of USMC vets of WW II. One such vet has an attack of vertigo while driving. A local policeman, noted for his aggressive tactics, pulls the vet to the curb for his erratic driving. During the ensuing questioning, the vet vomits on the cop's Blues. Enraged, the cop uses his ever present blackjack on the ex-Marine. The ex-Marine dies on the operating table.
Awareness of the vet's death, coupled with knowledge of this cop's short temper and rough tactics arouse a spirit of revenge in the Marine heroes buddies. They plot revenge, preferably by hit-and-run auto.
Once settled on a plan of action, the vets wait for an opportunity, which comes during an epic downpour. A positive ID was made by one of the vets, who contacted the others to proceed with the execution.
Unknown to the 'hit squad', The police had made a shift change after the plan was set in motion. The USMC vets actually killed the wrong cop!
The remainder of the story deals with a shoddy police investigation, police tunnel vision, local police meddling with State police policies, guilt, flight and a 'no consequence' aftermath.