Erle Stanley Gardner 
Bedrooms Have Windows [EPUB ebook] 

It started as a routine tail — shadowing an oily hustler who’d been courting a well-healed matron. But the assignment soon led Donald Lam to a sleazy hotel room with a sexy barfly. And now she’s left him high and dry with a pair of corpses dumped in his lap. Suddenly he’s the cops’ prime suspect. And it’ll take some fancy footwork to sidestep the law — and the real killer, who intends to leave Bertha Cool partnerless.