From Goodreads:

Book #11 in the Dave Brandstetter series

Author Joseph Hansen and his fictional sleuth Dave Brandstetter are both brand-name commodities in the mystery and gay fiction genres. In this 11th novel featuring the gay detective, Brandsetetter is called out of semi-retirement to investigate the apparently accidental shotgun deth of his lover's co-worker. Whst unfolds is a gripping tale of blackmail and murder set in a sleepy California town, where nothing is as innocent as it appears.