NORRISTOWN, Pa. (AP) - Bill Cosby's lawyers are proving quick to go on the attack as his sexual assault trial gets underway in suburban Philadelphia.

A judge Tuesday will decide if the mother of one of his accusers can testify.Kelly Johnson told jurors Monday that she told her mother after Cosby abused her in 1996 when she worked for his agent.She said she feared speaking out at the time because Cosby was "the biggest celebrity in the world."Cosby's lawyers questioned her credibility.Prosecutors called Johnson to try to show Cosby had a prior history of drugging and molesting women. Cosby is charged with assaulting a Canadian woman, who also is expected to testify.The AP does not typically identify people who say they are sexual assault victims unless they grant permission, which Johnson has done.