The Girl Who Wasn't There (Mac #8), by Thomas B. Dewey (epub/Kindle/pdf)
The trail Mac found himself trying to follow was very cold. Another private detective -- his friend Barry Henley -- had been killed a year earlier in a fall from a tenth-story window, and the cops had written it off as accidental. But when Hensley's widow told Mac that several people had tried to get into her apartment under various pretexts; when Mac found she was being followed; and when the mug shot she picked out of the police department files proved to be that of a very tough egg, Whiskey Davis -- suddenly Henley's death began to look like murder. Mac knew for sure when the next death couldn't have been accidental. A bomb that blows up car and driver when the ignition is turned is never anything but murder....
"Mac is one of our best private eyes." -- San Francisco Chronicle
"Thomas B. Dewey is one of detective fiction's severely underrated writers!" -- Bill Pronzini
"More than one rub-out for private eye Mac to run through when a man with a well-minked wife is shot down by a police sergeant from Steel City, outside of Chicago. Exit also for an attorney, a safecracker and assorted others who are linked to the importance of teenage Marianne, the rehabilitation project of moneyman Lloyd, and a series of black-mailing pictures. Scrappy all the way." -- Kirkus Reviews
"Mac has been called one of the most believable and humane PI's in crime fiction. He is reluctant to use either his gun or his fists, but will do so when the situation demands it, or in self-defense; he doesn't merely solve his clients' cases, but provides moral support and sympathy as well; and perhaps most notable of all, Mac feels, and is not afraid to show itópain, loss, sorrow, loneliness." --thrillingdetective.com