I would like to nominate Bad Boy Brawly Brown by Walter Mosley.
Review from Amazon:
Racial tensions and America's civil rights movement have previously figured into Walter Mosley's series about sometimes-sleuth Ezekiel "Easy" Rawlins. But Bad Boy Brawly Brown turns what had been a background element into compelling surface tension. The year is 1964, and though Easy seems settled into honest work as a Los Angeles custodian, he's having other problems--notably, his adopted son's wish to quit school and lingering remorse over the death (in A Little Yellow Dog) of his homicidal crony, Raymond "Mouse" Alexander. Yet he remains willing to do "favors" for folks in need. So, when Alva Torres comes to him, worried that her son, Brawly Brown, will get into trouble running with black revolutionaries, Easy agrees to find the young man and "somehow ... get him back home." His first day on the job, however, Rawlins stumbles across Alva's ex-husband--murdered--and he's soon dodging police, trying to connect a black activist's demise to a weapons cache, and exposing years of betrayal that have made Brawly an ideal pawn in disastrous plans.
Mosley's portrayal of L.A.'s mid-20th-century racial divide is far from simplistic, with winners and sinners on both sides. He also does a better-than-usual job here of plot pacing, with less need to rush a solution at the end. But it is Easy Rawlins's evolution that's most intriguing in Brawly Brown. A man determined to curb his violent and distrustful tendencies, Easy finds himself, at 44, having finally come to peace with his life, just when the peace around him is at such tremendous risk. --J. Kingston Pierce
I would like to second the nomination of Warsaw Spies