I had to do the perp walk through a gauntlet of paparazzi at the 28th Precinct and I must say I finally understood the impulse to put a coat over your head. It didn't take long for someone to recognize me. "Lt. Knight! Over here!" Lt. Summer Knight is the badass I play in my action movies. But now I'm home in Harlem reluctantly running the Harlem Journal, the weekly newspaper my Daddy left me when he just died. That's Pearl Washington talking. She's the hero of Harlem Hit & Run, a murder mystery set during one week in November 1990 between two editions of the Journal, as a community bank fails. Harlem is a complex character in the story. So is Pearl. She is studying the Buddha's teaching as part of her martial arts training and finds herself in a Buddhist moment when, for instance, she has to decide whether or not to arm herself. She chants over Cecelia Miller when her friend is hit and killed by a car on 125th...