Night Moves
Starring Gene Hackman with Melanie Griffiths and James Woods
Directed by Arthur Penn
1975
Gene Hackman's career is close to its 50th Anniversary, starting in 1959. This 1975 Warner Brothers production is a bit of a soap opera, but it is also a self aware one. The fact that it concerns the L.A. art and movie scene makes the self references meaningful and the soap makes this some fun 1970's popcorn. James Woods is very young in this movie, and Melanie Griffiths, even younger.
Moseby plays a straight up guy dealing with some rather nefarious dealings concerning the trust child daughter (Griffiths) of a former minor hollywood actress. His office, I believe, is the same one used by the TV series Starsky and Hutch.