Robert Card, the suspect in the Maine shootings that left 16 dead, he had tried to buy a silencer for a firearm three months before the attack.

However, the store owner refused to sell him the silencer after Card admitted he had a history of psychiatric problems.

Card was found dead Friday after a 48-hour manhunt by authorities.

The gunman opened fire at a bar and bowling alley Wednesday in the city of Lewiston, killing 18 people and injuring a dozen others.

Since then, details have come to light about Card, a 40-year-old Army reservist with a history of mental illness and an alleged violent past.

Maine gun store owner Rick LaChapelle told The New York Times and ABC News that the suspect entered his store on Aug. 5 to pick up a silencer he had purchased online.

He then had to fill out a form, which included a question asking: “Have you ever been hospitalized in a mental institution?” Card said yes, Mr. LaChapelle said.

Staff then reviewed the form and informed Card that he was ineligible to purchase the silencer due to the answers he had given on the questionnaire.

LaChapelle believes the attacks would have been more deadly if the market had been completed because people would not have heard the gunshots.

“We did what we had to do and hopefully we saved a lot of lives just by following the proper procedures,” he told The New York Times.