MISSOULA, Mont. (AP) - An expert witness called to testify at the rape trial of former University of Montana quarterback Jordan Johnson said he was there to educate the jury about the range of behaviors a rape victim can exhibit.

Clinical psychologist David Lisak said Thursday it's common for rape victims to blame themselves for what happened as a way of not admitting they've been raped or to figure out what they think they did wrong so they don't do that again.

Under cross-examination, defense attorney Kirsten Pabst got Lisak to acknowledge that while trauma could explain the changing stories of an alleged rape victim, lying could explain the same behavior.

Johnson is charged with raping a woman as the two watched a movie at her residence on Feb. 4, 2012.