Sean Kingston is behind bars in Southern California, an arrest that came hours after cops raided his home in Florida and arrested his mother. The singer was arrested Thursday evening in on the base of Fort Irwin -- out in the middle of California's Mojave Desert -- and cops say he will be booked into the San Bernardino County Jail. Cops say Sean had performed a show on the base, and afterward he cooperated as the base police took him into custody on a Broward County Sheriff's Office arrest warrant for fraud and theft charges. The arrest bookends a busy day for Sean and his family with law enforcement. As we reported, the Broward Sheriff pulled off a raid Thursday morning at Sean's home in Southwest Ranches, FL. Cops arrested his mother, Janice Turner, on the same fraud and theft charges he's facing ... and also confiscated a bunch of merchandise from his home. TMZ got photos inside Sean's home right after the raid which showed a massive LED screen in one of his rooms. Attorney Dennis Card was there representing his client ... a company that sued Sean for not paying the $150,000 home entertainment system. The screen was dismantled -- panel by panel -- and removed from the house. Prior to his arrest, Sean reacted to the raid, and his mother's arrest, on social media ... where he claimed his "lawyers are handling everything as we speak." Next up on the agenda for those lawyers ... bail!