A clinical psychologist contracted to work at a California military base has been charged with raping some of the female service members he was treating for post-traumatic stress as a result of previous sexual assaults. Officials on Tuesday said Heath J. Sommer is facing three felony sexual assault charges for crimes allegedly committed in 2014 and 2015 at Travis Air Force Base’s David Grant Medical Center. Prosecutors say Sommer claimed to be using a treatment called exposure therapy when he asked the women to have sex with him, leaving them “even more traumatized.” One of the women reportedly received therapy after being raped in 2002 while on deployment in Afghanistan. Sommer allegedly encouraged her to relive her sexual assault by sleeping with him so she could have a “positive and loving” experience. Air Force officials said a background check was done on Sommer but “nothing popped up.” “We take sexual assault very seriously,” base spokeswoman Tonya Racasner said, adding that the psychologist was suspended as soon as the allegations surfaced.