An East Bay man was convicted of several felonies — including conspiring with two rival pimps — in what authorities have described as the worst sex trafficking case in Contra Costa’s history.

Derrick Harper, 39, was convicted Thursday of kidnapping for extortion, aiding and abetting rapes, conspiracy to commit human trafficking, and other related offenses. He was charged in 2013, along with two East Contra Costa men, Roy Gordon, 45, and Eric “E-Rock” Beman, 49.

READ MORE