The man authorities have identified as a suspect in the mass shootings in Maine is an Army Reservist who was hospitalized for a medical evaluation in July after he acted “erratically,” according to U.S. military officials.

Sgt. 1st Class Robert R. Card II, a U.S. Army spokesman said, enlisted in December 2002 and is a petroleum supply specialist who has not deployed for combat.

“On July 16, 2023, leaders of the Army Reserve’s 3rd Battalion, 304th Infantry Regiment, which was billeted at the Camp Smith Training Site while training at the United States Military Academy, informed garrison staff that Army Reserve Sgt. 1st Class Robert Card was behaving erratically. Out of concern for his safety, the unit requested that law enforcement be contacted,” the New York National Guard said in a statement sent to The Atlanta Journal-Constitution Thursday.

“New York State Police responded and transported Card to Keller Army Community Hospital at the United States Military Academy for medical evaluation.”

The New York State Police declined to comment, citing a continuing investigation

Card 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, Katie Card, who is married to his brother, told NBC News. She also told NBC her family reached out to police and the Army Reserve base where he serves because they “got increasingly concerned” in the last few weeks.

“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.”

The shootings Wednesday left 18 dead and 13 injured, Maine. Gov. Janet Mills said during a news briefing Thursday morning. A man shot and killed the victims at a bowling alley and restaurant in Lewiston, the Associated Press reported, and then fled, prompting a massive search by authorities and a shelter-in-place advisory. Mills said Card is considered armed and dangerous.

“This city did not deserve this terrible assault on its citizens, on its peace of mind, on its sense of security,” the governor said, according to the AP.

Card — who is assigned to the 3rd Battalion, 304th Infantry Regiment in Saco, Maine — has received the Army Reserve Component Achievement, the Humanitarian Service and the National Defense Service medals and the Army Service Ribbon, a military spokesman confirmed Thursday.

“We take matters such as this very seriously,” the Army said in a statement Thursday, “and our primary concern is ensuring that all legal and appropriate actions are taken in accordance with our commitment to upholding the highest standards of conduct among our soldiers and civilian personnel. We will continue to collaborate and support local, state, and federal law enforcement agencies.”

President Joe Biden issued a statement about the shootings Thursday, saying “our nation is in mourning after yet another senseless and tragic mass shooting.”

“For countless Americans who have survived gun violence and been traumatized by it, a shooting such as this reopens deep and painful wounds,” Biden said. “Far too many Americans have now had a family member killed or injured as a result of gun violence. That is not normal, and we cannot accept it.”

Atlanta Mayor Andre Dickens said, “Time and time again, we have seen needless loss of life because of the deadly combination of mental health issues and ease of access to guns. I, along with other mayors, have been calling on Congress and legislatures to pass commonsense gun laws and I will continue to join my colleagues in urging our leaders at the federal and state levels to use their power to keep our communities safe.”

Federal lawmakers from Georgia also weighed in.

“Living with rampant gun violence isn’t freedom,” U.S. Sen. Raphael Warnock said in a social media post. “Congress must act and stop these tragedies before they begin.”

U.S. Rep. Buddy Carter posted, “America is experiencing a mental health crisis that must be taken seriously. Thank you to the brave officers who are protecting and serving the Lewiston community.”

AJC staff writer Adam Van Brimmer contributed to this report.