The suspect behind a string of deadly shootings in Maine was turned away by a local firearms store three months before he opened fire.
Robert Card was refused a silencer for a firearm after he admitted that he was committed to a mental health facility, a local store owner said.
Card was found dead on Friday, ending a 48-hour manhunt.
The gunman had opened fire at a bar and a bowling alley on Wednesday in the city of Lewiston, killing 18.
More than a dozen people were also injured in the shooting.
Since then, details have emerged about Card, a 40-year-old army reservist with a history of mental illness and who had allegedly made violent threats in the past.
Maine firearms store owner Rick LaChapelle told The New York Times and ABC News that the suspect had entered his shop on 5 August to pick-up a silencer he had purchased online.
He then had to fill out a form, which included a question that asked: “Have you ever been committed to a mental institution?”
Card answered yes, Mr LaChapelle said.
The staff then looked at the form and informed Card that he was not eligible to purchase the silencer because of the answers he’d given on the questionnaire.
Mr LaChapelle said he believes the attacks would have been deadlier had the purchase gone through, because people would not have heard the gunfire.
“We did what we were supposed to do and hopefully saved a lot of lives by just following the proper procedures,” he told the New York Times.
Card was committed to a mental health facility for two weeks in July for acting erratically, “hearing voices and threats to shoot up” a military base, the Associated Press reported.
Police have confirmed that Card was known to have undergone mental health evaluations but that he had never been forcibly committed for treatment.
Later in September, the Maine National Guard had issued a state-wide warning about Card, saying that they feared he would “snap and commit a mass shooting”, according to law enforcement sources who spoke to CNN.
The warning came after Card allegedly made threats against his US army base in Saco, Maine.
Officers in Sagadahoc County and Kennebec County then tried to contact Card on 16 September, less than six weeks before the deadly shooting rampage in Lewiston, but were unable to find him at his home.
Card’s history of mental illness and alleged threats and have raised questions about whether Maine’s “yellow flag” law, which passed in 2019, is effective in preventing deadly mass shootings.
The law outlines several steps that have to be taken before a weapon can be taken from someone who is deemed to pose a threat to themselves or others.
It is seen as a weaker version of a “red flag” law, which has been adopted in some form by 21 other states. Those laws allow a court to order the temporary removal of a firearm from a person who may be a danger to themselves or others.
Cam Shannon, chair of the non-profit Maine Gun Safety Coalition, called the state’s gun laws “woefully weak” in an interview with NBC News.
“We have long felt that this is a question of not if, but when,” Ms Shannon said.
Card was found dead from an apparently self-inflicted gunshot wound on Friday night, police said, near a river around 10 miles (16 kilometres) from Lewiston.
