Card, a former hand grenade instructor, led police on a three-day manhunt before he was found dead.

“We will never know whether he would have committed the mass murder even if someone had managed to take his firearms away from him before October 25,” Daniel Wathen, former chief justice of Maine and chairman of the commission, told reporters on Tuesday.

“However, the Commission agrees that there were several options which, if exploited, could potentially have changed the course of these tragic events.”

The 215-page report states that police had the authority to confiscate Card’s weapons and take him into protective custody weeks before the shooting under Maine’s Yellow Flag Law.

However, the findings were particularly critical of the leaders of the local Army Reserve units, who, according to Wathen, failed to “exercise their authority over him and take the necessary steps to reduce the threat he posed to the public.”

The US Army Reserve told the BBC that administrative action had been taken against three officers due to failures in Card’s chain of command.

It was also said that the Army Reserve was making changes to its mental health program and leadership training.

“We remain deeply saddened by these events and continue to mourn with the people of Maine, the victims and their families,” said spokesman Bryce Dubee.

The report found that Card’s supervisor knew months before the shooting that Card was suffering from auditory hallucinations, behaving aggressively, collecting weapons and making “ominous comments.”

“They ignored the urgent recommendations of Card’s psychiatrists to continue to care for him and take steps to remove weapons from his home,” Wathen said.

The Army Reserve also failed to share information about Card’s threatening behavior with other appropriate authorities, including the sheriff’s office. Mr. Wathen said some of the commission’s requests for information to the Army remain unanswered.

The Sagadahoc County Sheriff’s Office had previously stated that the Army Reserve withheld important information from law enforcement, preventing officials from taking appropriate action.

However, the report says state authorities had enough information to confiscate Card’s firearms by September 2023 without the Army’s help.