I'll Kill You Next — Lawrence Lariar

When the heir to a comic strip empire is rubbed out, Manhattan private eye Steve Conacher is drawn into a colorful spread of nasty secrets.
 
When popular cartoonist Lawrence Lariar decided to moonlight as a mystery writer, creating comic book artist turned amateur sleuth Homer Bull was a natural. From the 1940s through the 1960s, Lariar continued to switch from sketching caricatures to sketchy characters, writing hardboiled crime fiction under his own name as well as the pseudonyms Michael Stark, Adam Knight, Michael Lawrence, and Marston La France, and creating a series of memorable gumshoes. Now his classic whodunits are available as ebooks.
 
A little man built for big trouble, private eye Steve Conacher finds plenty of it when his old friend, Mike Smith, disappears. Odd timing considering the talented cartoonist was set to take over a million-dollar comic strip from his ancient and ailing mentor. Anyone would kill for that gig. That's why it makes more sense when Mike is fished out of an icy river, stone cold dead.
 
So who erased the new prince of pen and ink? Right now, Conacher is looking at three characters in Mike's shady background: the bereaved widow, the hot career girl he was dating, and the ambitious wife of a rival artist. But it's the second murder that leaves Conacher's head spinning. Now he has a fresh set of motives, and a brand-new target in the killer's sights: himself.
 
I'll Kill You Next is the 6th book in the PI Steve Conacher Mysteries, but you may enjoy reading the series in any order.