The Counterfeit Murder in the Museum of Man by Alfred Alcorn

When Norman de Ratour discovers the body of Heinrich von Grümh in a car outside his beloved Museum of Man, he knows he faces a sticky public relations mess. What he doesn’t know is that the gun used to kill the honorary curator is his own Smith & Wesson revolver. Implicated, publicly embarrassed, his life’s work in danger, Norman becomes the prime per- son on a list of unusual suspects.
Along the way, he both lives with and is aided by Alphus, former denizen of the Primate Pavilion and a creature who has an intellect to be reckoned with as well as a low, finely ar- ticulated opinion of the human species.