Lawrence Block 
Hit Parade [EPUB ebook] 

Keller is friendly. Industrious. A bit lonely, sometimes. If it wasn’t for the fact that he kills people for a living, he’d be just your average Joe. The inconvenient wife, the troublesome sports star, the greedy business partner, the vicious dog, he’ll take care of them all, quietly and efficiently. If the price is right.Like the rest of us, Keller’s starting to worry about his retirement. After all, he’s not getting any younger. (His victims, on the other hand, aren’t getting any older.) So he contacts his "booking agent, " Dot, up in White Plains, and tells her to keep the hits coming. He’ll take any job, anywhere. His nest egg needs fattening up.Of course, being less choosy means taking greater risksand that could buy Keller some big trouble. Then again, in this game, there are plenty of opportunities for some inventive improvisation . . . and a determined self-motivator can make a killing.