Thes are not the same authors as Diane Mott Davidson.
1)Acccording to "The Gay Detective Novel" by Judith A. Markowitz, "Diane Davidson (1933-; pseudonym for Diane Bunker) is a single parent who was born and still lives in southern California. The Toni Underwood mysteries are the only novels she's published." pg. 42.
2)Marie Diane Davidson