Donald E. Westlake 
Don’t Lie to Me [EPUB ebook] 

Working night security at a museum, ex-cop Mitchell Tobin finds a naked corpse on display in this crime novel by the Edgar Award–winning author.  When he first met Linda Campbell, Mitchell Tobin was nothing more to her than the man who had put her husband in jail. It took over a year for them to begin their affair, but once it started, it became intense—lasting right up to the day when Tobin shirked duty to see her, and his partner got killed as a result. Years later, on a penny-ante night security job, Tobin is doing his rounds when Linda comes to ask a favor. Out of prison and hoping to go straight, her husband is having trouble escaping his old cronies. Tobin has just agreed to try to help when they come upon a corpse, lying naked on the floor. If he’s to do anything for Linda, Tobin will have to keep clear of the murder investigation. But as her husband knew all too well, it takes much more than self-discipline to put a checkered past behind you.