I’m pretty sure I’ve read this once aeons ago. I couldn’t remember anything specific about it, but I was getting feelings of deja vu, especially in the courtroom. Of course, that might just be because Perry Mason started getting super formulaic near the end — I might have just read an identical story with the names changed.
A syndicate is trying to buy out a small motel casino in Las Vegas and build a large resort. Three shareholders have sold but the other two are holding out for a better price. The racketeer trying to buy them out finds himself shot to death. Notable for most of the novel being immaterial to the case, which resolves itself rather suddenly when a witness for the prosecution inexplicably breaks down on the stand and confesses to the crime.