Ex-DA expected to be key defense witness at Cosby hearing

PHILADELPHIA -- An ex-prosecutor is expected to testify that he promised Bill Cosby would never be charged over a Pennsylvania sex-assault complaint, but a judge must decide if that constitutes an immunity deal.[br /][br /]Then-District Attorney Bruce Castor will be a key defense witness at a Feb. 2 hearing to determine if the case is thrown out.[br /][Ads /][br /]The defense argues that prosecutors who arrested Cosby last month[/url] unfairly used his deposition testimony from the accuser's 2005 lawsuit against him. Castor supports their position.[br /][br /]But new District Attorney Kevin Steele says there's no evidence of a signed immunity agreement. And accuser Andrea Constand's lawyer says she doesn't know of one.[br /][br /]The deposition shows Cosby testifying that he gave Constand wine and pills before performing a sex act. He calls it consensual. She says she was drugged and violated.