Erle Stanley Gardner 
The D.A. Calls it Murder [EPUB ebook] 

The little clergyman had died peacefully in bed in the Madison Hotel. But Douglas Selby, recently elected District Attorney, suspected there was more to this death than meets the eye, and soon knew that something was definitely wrong. So Doug finds himself faced not only with a wily murderer, but with virulence from a hostile press, reluctant witnesses, and a film star unwilling to explain why she was on the spot.