Can you dig it?

As part of its "Watching the Detectives" series, the Brattle Theatre screens a movie tonight about a private investigator, who is also a sex machine, who risks his neck for his brother man, who does not cop out, and who is understood by his woman even though he is quite complicated. We are, in fact, talking about "Shaft." And, thankfully, we're talking about the 1971 film starring Richard Roundtree, not the more recent remake starring Samuel L. Jackson. 5:15, 9:45. Tickets: $9.50. Brattle Theatre, 40 Brattle St., Cambridge, 617-876-6837. brattlefilm.org