King of the Weeds — Max Allan Collins; Mickey Spillane

The Mafia, a serial killer, the government -- everyone is out to get PI Mike Hammer in this relentless thriller featuring Mickey Spillane's “customary mixture of violence and witty dialogue” (Booklist)
 
He was the killer and I was the target.

It should be a mellow time for America's toughest PI. He and Velda are planning their nuptials, and Captain of Homicide Pat Chambers is nearing retirement. Then an assassin's bullet almost brings Mike down on his office doorstep. Could the attempted hit have anything to do with the impending release of a serial killer put away by Mike and Pat? 
 
There's also the small matter of the $89 billion in Mafia money stashed in a cave, in a location known only to Hammer. With everyone from wiseguys to the US Government on his tail, Mike must prove that he is just as sharp, and deadly, as ever.