Johannes Mehserle, the BART police officer who shot Oscar Grant in the back while he was lying face down on the floor and restrained, has been arrested, a day after BART officials announced they had concluded their investigation into the shooting. The probe had been delayed by the holidays and the tone-deafness of public officials.

— A. Serwer

Adam Serwer is a writing fellow at The American Prospect and a graduate of the Columbia University Graduate School of Journalism. He also blogs at Jack and Jill Politics and has written for The Village Voice, The Washington Post, The Root, and the Daily News. Follow @adamserwer