As federal prosecutors called witnesses to the stand in Sean "Diddy" Combs' criminal trial, his ex-girlfriend, the R&B singer Cassie Ventura, continued her testimony Wednesday inside the New York City courthouse as the trial entered its second day.

According to the indictment, Combs — also known as “Puff Daddy,” “P. Diddy,” and “Diddy” — “abused, threatened, and coerced women and others around him to fulfill his sexual desires, protect his reput...