A mistrial was declared Wednesday in the court-martial of former squadron commander Lt. Col. Keithen Washington, who was accused of assaulting and sexually assaulting a civilian woman with whom he was in a relationship.

“The judge declared a mistrial because he heard testimony he felt could negatively impact the panel’s ability to impartially consider all the evidence,” Lt. Col. Darrick Lee, director of public affairs for the Air Force District Washington at Joint Base Andrews in Maryland, said in an email Thursday.

Opening statements in the court-martial were heard Tuesday at Joint Base Andrews in Maryland. He faced one specification of a charge of sexual assault, and five specifications of a charge of assault. Two of the alleged assaults are said to have taken place while Washington was commander of the 86th Force Support Squadron at Ramstein Air Base in Germany.

Court-martial resumes for former squadron commander accused of sexual assault and assaults Washington is accused of sexually assaulting a civilian woman with whom he was in a relationship, and repeatedly hitting her in 2014 and 2015. Two of the alleged assaults took place while he was a squadron commander at Ramstein Air Base in Germany.

His court-martial first began at Andrews last October, but was postponed until this week due to a scheduling issue.