The signs were all there. Why didn’t anyone stop the shooter in Maine?

Robert Card showed a series of textbook warning signs: he heard voices. He told people he was planning violence. And his behavior had clearly changed in the months leading up to the mass shooting he carried out last week.

His family, his superiors in the military and the local police all knew this. Yet no one stopped him.

His killing of 18 people with an assault rifle in Lewiston, Maine, highlights how deficiencies in the mental health system, weak laws and an unwillingness to threaten personal freedoms can derail even concerted efforts to thwart violence in a country overrun by guns .

“So often I think we talk about how to get people on the radar,” said Jillian Peterson, executive director of the Violence Project, which researches perpetrators of mass shootings. “And in this case, he was on the radar of many different systems, and they still couldn’t get him to intervene.”

Police records, including accounts from relatives and colleagues in his Army Reserve unit — one of whom sent an anguished late-night text message to his supervisor six weeks before the shooting — show that Mr. Card’s friends and relatives had grown increasingly worried about the shooting. his mental state.

But even when they communicated with each other and with the police, even when he was confronted and hospitalized and a deputy came to the door, nothing went far enough.

J. Reid Meloy, a forensic psychologist and FBI consultant on mass shooting prevention, said Mr. Card received “a Band-Aid treatment” for a seriously serious condition.

“If you have multiple jurisdictions and there is a silo effect, you increase the risk of failure,” he said.

After the shooting, Mr. Card’s siblings told police that their brother had been dating a woman he met at a cornhole game at Schemengees Bar & Grille — the bar he later attacked — and that he became delusional in February after they had an argument. “bad break,” according to affidavits released Tuesday by Maine State Police.

Mr. Card’s sister, Nicole Herling, said he had been prescribed medication but had stopped taking it, according to the police affidavit.

He wrongly believed that several businesses in the area, including the two he attacked, were broadcasting online that he was a pedophile, she said.

Ryan Card told a police officer that he had tried to help his brother, but he was “not to be argued with,” the affidavit said.

The first public report of family members informing police of their concerns came in May, when Mr. Card’s teenage son and ex-wife reported that he had become paranoid and angry and took 10 to 15 guns from his brother’s home had brought.

A Sagadahoc County sheriff’s deputy, Chad Carleton, initiated an ad hoc intervention process, exchanging information with both Mr. Card’s Army Reserve Command, which said it was aware of his problems but not the severity, and his brother, who had witnessed Robert drinking heavily and making “angry rants about having to shoot someone.”

Despite these threats, Deputy Carleton told Ryan Card to reach out in the future if he believed his brother was a danger to himself or others, implying that the department would then take action.

Ms. Peterson and other experts on mass shootings say this is a common misstep. Somewhere between 60 and 90 percent of perpetrators “leak” their plans in advance to other people. But people don’t take them seriously enough, or let the person who made the threat convince them it’s not sincere.

“He literally said, ‘I am a danger to others. I want to photograph this place.’ So that should be enough to escalate it,” Ms. Peterson said.

Instead, Mr. Card’s siblings visited him. He answered the door with a gun in hand, but agreed to see a doctor about the paranoia and the voices, according to Deputy Carleton’s report.

Neither Mr. Card’s relatives nor Deputy Carleton responded to requests for interviews; Sagadahoc County Sheriff Joel Merry said in a statement that he believed his agency had “acted appropriately and followed procedures” but that he would review his policies to look for improvements.

The Army Reserve’s plan at the time was “to sit down with Robert in the near future and see if they could get him to speak out about what was going on.” Asked for comment, a spokesman said the military was continuing to investigate Mr. Card’s service record.

It is not clear how both plans turned out. But it is clear that Mr Card’s son and ex-wife had become afraid of him. They didn’t want him to know they had gone to the authorities and tried to keep their involvement confidential.

Experts said a stigma against “snitching” or fear of retaliation can make people hesitant to notify authorities, or go back to them a second or third time when someone needs help.

Dr. Meloy said family members had legitimate fears: “They should alert the police; on the other hand, alerting the police – and then a paranoid person finding out – can trigger a backlash.”

In July, Mr. Card again came to the attention of authorities when he and his Army Reserve unit attended annual training at Camp Smith in New York. There, according to police records, Mr. Card accused three soldiers of calling him a pedophile, pushed one of them away and locked himself in his room.

Mr. Card was taken to a U.S. Military Academy medical treatment facility at West Point, and from there to a civilian psychiatric hospital in New York called Four Winds, where he stayed for 14 days.

But the system for treating people who are unable to get help on their own focuses on acute, not long-term, problems. Involuntary stay requires an imminent threat of harm and typically lasts from 72 hours to two weeks.

After Mr. Card’s discharge from hospital, the military ordered him not to have access to military weapons and not to participate in live-fire activities, declaring him “non-deployable.”

According to an Army statement, reserve medical personnel made multiple attempts to contact Mr. Card over the coming months.

Those decisions only affected what happened during Mr. Card’s watch. But reservists like him are rarely on duty, so commanders are limited to alerting civilian authorities they may not know, said Michael Aschinger, a retired Army Reserve sergeant major.

That left local police with two legal options. They used neither.

First, an involuntary psychiatric commitment should have made it illegal under federal law for Mr. Card to own guns. Neither the military nor the hospital will say whether his stay at Four Winds was forced, but there are several indications that it was, including the fact that just two days after returning home he wrote on a weapons purchase form that he had been committed. . (The form does not specify this, but the federal law on which this question is based does not apply to voluntary commitment.)

Any involuntary commitment should have been reported to a national database that would have prevented Mr. Card from passing the background check required to purchase guns from a licensed dealer. Officials have said that Mr. Card’s name was not in the database and that he legally purchased guns after his hospital stay.

Regardless, Mr. Card could have avoided a background check by purchasing a gun from a private dealer. And while the law prohibits people against whom a crime has been committed from owning guns, there is no automatic mechanism for removing guns they already own.

The local sheriff’s office was notified of Mr. Card’s hospitalization after another shocking incident in September, but apparently did not use this as a possible means of taking away his guns.

At that point, the warning signs couldn’t have been clearer.

During a car ride in mid-September, Mr. Card punched a fellow soldier and threatened to “shoot up” the Army Reserve facility in Saco, Maine, and other places. According to a copy of the messages obtained by The New York Times, the soldier texted a senior officer at 2 a.m., warning him to change the passcode for the unit’s gate at their base and to be armed in case Mr. Card approached.

“I believe he is confused,” wrote the soldier, identified as Staff Sergeant Hodgson, adding that he loved Mr. Card “to death” but “I don’t know how to help him and he refuses help to seek help or to continue helping.”

“I believe he is going to shoot and do a mass shooting,” he wrote.

A copy of the text message was included in a letter that Kelvin Mote, a first sergeant in the Reserves and a corporal with the Ellsworth Police Department in Maine, sent to the sheriff’s office in mid-September detailing the incidents during annual training and hospitalization were described. and car ride.

Delegates could also have tried to use Maine’s “yellow flag” law, which allows police to remove a person’s weapons for up to a year if that person shows “a likelihood of foreseeable harm.” The law went into effect in 2020 and has been used 81 times, but never by the Sagadahoc County Sheriff’s Office, according to state records.

All law enforcement officers in the state receive training on how to use the law, which means taking the person into custody, arranging a medical evaluation and presenting the results to a judge.

The law is tougher than “red flag” laws in other states, which do not require people to be taken into custody and evaluated.

When the Sheriff’s Office received the Army report in mid-September, Sgt. Aaron Skolfield went to do a welfare check but did not find Mr. Card.

Instead, Sergeant Skolfield worked with Ryan Card, who said he and his father figured out a way to secure Mr. Card’s weapons.

But it never happened. Ryan said his brother allowed him to change the code on his gun safe for “a certain period of time” a few months ago, according to a police affidavit. But Robert Card, it said, “still had access to his firearms before the shooting.”

John Ismay And Dave Phillips reporting contributed. Kirsten Noyes research contributed.