The family of the Army reservist accused of fatally shooting more than a dozen people in Lewiston, Maine, alerted police and military officials that he was experiencing an “acute” mental health episode before the Wednesday night massacre, the suspect’s sister-in-law said.

Robert Card, 40, a firearms instructor and longtime member of the Army Reserve, began to hear voices that were saying “horrible” things about him a couple of months ago when he was fitted for high-powered hearing aids, according to Katie Card, who is married to his brother.

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“He was picking up voices that he had never heard,” she told NBC News. “His mind was twisting them around. He was humiliated by the things that he thought were being said.”

Katie Card said the family did their best to reassure Robert Card that the comments were not real, including by verifying with some of the people he claimed had made the remarks.

But, she said, “it turned into a manic belief.”

“He was just very set in his belief that everyone was against him all of a sudden,” she said.

Robert Card, who was still at large early Thursday afternoon, is accused of killing at least 18 people and injuring many others at a bar and bowling alley, police said.

His sister-in-law said the family reached out to police and the Army Reserve base where he serves as they “got increasingly concerned” in the last few weeks.

“We just reached out to make sure everyone was on the same page because he is someone who does gun training,” she said. “We were concerned about his mental state. That’s all.”

Her husband went “back and forth” with the Army, Katie Card said.

“They were following up on it, too, but he’s never been someone we thought would actually do anything,” she said.

The Army, which confirmed Robert Card’s status with the Reserve, did not immediately respond to a subsequent request for comment by NBC News about the family’s warning.

Two senior law enforcement officials told NBC News that Robert Card’s military unit commanders sent him to receive psychiatric treatment this summer after they became concerned about threats he made to the base and his claims that he was hearing voices.

Robert Card spent about two weeks undergoing in-patient psychiatric treatment and was released, according to the officials. It is not clear what further action was taken.

A Defense Department official said that Card’s unit requested law enforcement be contacted in July after he began behaving erratically. New York State Police responded and transported Card to Keller Army Community Hospital at the United States Military Academy for medical evaluation.

Katie Card declined to discuss whether the family tried to restrict his access to firearms.

The senior law enforcement officials said the weapon used in the attack was a sniper rifle with .308 caliber bullets, and that it was purchased legally in 2023.

Robert Card enlisted in the Army Reserve in December 2002 and had no combat deployments, an Army spokesperson said.

His sister-in-law said he had severe hearing loss likely due to being around constant gunfire. 

She said the family has been continuously messaging him to tell him he’s loved and that “he needs to do the right thing” but has not heard from him. 

Katie Card said her brother-in-law is a “wonderful person” and a great father to his son who just graduated high school. She said his behavior change was sudden and that he had not previously experienced mental health issues.

“We don’t know this person. This is not him,” she said. “We are so sorry for the pain he’s caused others.”