Ohio ? Before killing himself with a single gunshot, Pvt. Keiffer Wilhelm called his mother twice from Iraq and told her he was being targeted in his new unit and forced to run for miles with rocks in his pockets that smashed against his knees.

He told her he hated it, she said in an interview with The Associated Press on Thursday, marking the first time anyone has said Wilhelm spoke to them about the abuse.

“He said ‘Mom, I don’t have anybody to turn to here,”‘ said Kathe Wilhelm, recalling the last conversation she had with her son, a day before he died.

The investigation into Wilhelm’s death has led to charges against four soldiers who the military says were mistreating some of the men in their platoon. Allegations include verbal abuse, physical punishment and ridicule toward the soldiers.

The military has said there’s no direct evidence, so far, that the alleged misconduct caused Wilhelm’s death.