Singer Bobby Brown began his jail sentence in Los Angeles Wednesday, following his third driving under the influence conviction, TMZ reported. Brown was sentenced last month to 55 days in jail in connection with his October 2012 DUI arrest. He also was placed on four years probation and will have to complete an 18-month alcohol program, TMZ said. Brown, who has a history of substance abuse, was the ex-husband of the late pop star Whitney Houston, who drowned in a hotel bathtub in February 2012 after drinking and using drugs.