PITTSBURGH (AP) — A former Pennsylvania gymnastics coach has pleaded guilty to sexually assaulting a teenage girl. Forty-eight-year-old Keith Callen of Sarver pleaded guilty Monday to aggravated indecent assault, sexual assault by a sports official and other offenses. Allegheny County prosecutors say Callen began molesting a 14-year-old gymnast in 2013. Authorities say the assaults continued for nearly two years. Prosecutors agreed to a prison sentence of two to four years in exchange for the plea.