Police teams had twice cleared a recycling centre where the body of the man suspected of killing 18 people was found on Friday night, officials in the US state of Maine have said.

Robert Card, 40, of Bowdoin – a firearms instructor who grew up in the area – was found dead in nearby Lisbon from a self-inflicted gunshot wound after the rampage in the city of Lewiston which left another 13 people injured.

Department of public safety commissioner Michael Sauschuck said the teams that cleared the recycling facility had included a tactical squad.

He said another state police team returned and found Card’s body on Friday night.

Mr Sauschuck said Card’s body alongside several guns in a trailer that had not been searched.

Authorities said Card likely launched his rampage as a result of underlying mental health issues.

Jim Ferguson, the Bureau of Alcohol, Tobacco and Firearms special agent in charge in Boston, told The Associated Press that the weapons used in the shooting had been purchased legally. Many firearms were recovered although he declined to say their make, model or how many exactly.

“There were a lot more than three,” Mr Ferguson said.

Maine Governor Janet Mills called for the healing process to begin at a news conference on Friday night.

She said: “Like many people, I’m breathing a sigh of relief tonight knowing that Robert Card is no longer a threat to anyone.”

Street life returned to Lewiston on Saturday morning after a days-long lockdown in the city of 37,000 following the shooting.

Businesses had been closed for days as police searched for the man who fatally shot 18 people at a bar and a bowling alley in Maine’s second largest city.

At a press conference, Mr Sauschuck said Card had a history of mental illness. As for why Card chose his targets, Mr Sauschuck said it was likely due to paranoia, that “people were talking about him and there may even have been some voices at play”.

Mr Sauschuck said there was no evidence that Card had ever been involuntarily committed to a mental health facility. A simple evaluation or voluntary commitment would not have triggered a prohibition on owning a gun, he said.

Under Maine’s yellow flag law, law enforcement can detain someone they suspect is mentally ill and poses a threat to themselves or others. The law differs from red flag laws in that it requires police first to get a medical practitioner to evaluate the person and find them to be a threat before police can petition a judge to order the person’s firearms to be seized.

“Just because there appears to be a mental health nexus to this scenario, the vast majority of people with mental health diagnosis will never hurt anybody,” Mr Sauschuck said.

He also said a note found in Card’s home was meant for a loved one with the passcode to his phone and bank account numbers. Mr Sauschuck said he would not describe it as an explicit suicide note but that the tone indicated that this was Card’s intent.

Mr Sauschuck said earlier that Card was found at 7.45pm local time (12.45am BST) near the Androscoggin River, about eight miles south-east of where the second shooting occurred on Wednesday evening.

He declined to divulge the location but an official told The Associated Press the body was at a recycling centre from which Card had been sacked.

US President Joe Biden said he was “grateful” that Maine residents no longer had to hide in their homes and in a statement called on congress to take action on gun violence.

The deadliest shootings in Maine’s history stunned a state of 1.3 million people that has relatively little violent crime and suffered only 29 killings in all of 2022.

In Lewiston, the 37,000 residents and those in surrounding communities were told to stay in their homes as hundreds of police officers, sheriff’s deputies, FBI agents and other law enforcement officials swarmed the area.

Card was a US army reservist. Leo Madden, who said he ran Maine Recycling Corp for decades, told the AP that Card worked there for a couple of years and nothing about him stood out. Mr Madden said he did not remember when Card was employed or whether he was fired or quit.

Last summer, Card underwent a mental health evaluation after he began acting erratically during training, a US official told the AP.

A bulletin sent to police across the country shortly after the attack said Card had been committed to a mental health facility for two weeks after “hearing voices and threats to shoot up” a military base.

A US official said Card was training with the army Reserve’s 3rd Battalion, 304th Infantry Regiment in West Point, New York, when commanders became concerned about him.

State police took Card to the Keller Army Community Hospital at West Point for evaluation, according to the official.

On Wednesday, Card attacked the bowling alley first, then went to the bar. Police were quickly sent to both locations but Card was able to escape.

For the next two days authorities scoured the woods and hundreds of acres of Card’s family-owned property, and sent dive teams with sonar to the bottom of the Androscoggin River.

Hours before Card’s body was found, the names and pictures of the 15 men, two women and 14-year-old boy who died in the shootings were released at a news conference.

The Maine Department of Public Safety said it would open a Family Assistance Centre in Lewiston starting on Saturday morning to offer help and support to victims at the Lewiston Armory.

The victims of the shootings include Bob Violette, 76, a retiree who was coaching a youth bowling league and was described as devoted, approachable and kind. Auburn city councillor Leroy Walker told news outlets that his son, Joe, a manager at the bar and grill, died going after the shooter with a butcher knife. Peyton Brewer-Ross was a dedicated pipefitter at Bath Iron Works whose death leaves a gaping void in the lives of his partner, young daughter and friends, members of his union said.

The Maine Educational Centre for the Deaf said the shootings killed at least four members of their community.

Tammy Asselin was in the bowling alley with her 10-year-old daughter, Toni, and was injured when she fell in the scramble as the shooting began. She had said she hoped the gunman would be found alive because she and her daughter had many questions that they hoped he could answer.

On Saturday morning, she told the AP in a text message that her daughter was relieved by the news, and she was now able to sleep peacefully.

“I am relieved as well, but also saddened at a lost opportunity to learn as much as we can,” she said.

“Now we are on the journey to heal, and I am looking forward to working on this. It will be difficult but I’m optimistic we will be stronger in the long run.”

On Saturday, Pope Francis sent a telegram to the bishop of Portland, Robert Deeley, saying he was “deeply saddened to learn of the terrible loss of life resulting from the mass shooting”.

Authorities have said publicly that the gunman used at least one rifle. They have not released any other details, including how the suspect obtained the firearm.

Authorities found a suicide note at a home associated with Card on Thursday that was addressed to his son, the law enforcement officials said. They said it did not provide any specific motive for the shooting.

The Lewiston shootings were the 36th mass killing in the United States this year, according to a database maintained by The Associated Press and USA Today in partnership with Northeastern University.