Police teams had already searched a recycling centre in Maine twice before eventually finding the body of the man suspected of killing 18 people in Lewiston, authorities said on Saturday.

Department of Public Safety Commissioner Michael Sauschuck admitted the teams had scoured the Maine Recycling Corporation property that features as many as 60 trailers on Thursday night. He said another state police team returned to the site on Friday and found Robert Card’s body in a trailer that hadn’t been searched.

The 40-year-old Card of Bowdoin – a firearms instructor who grew up in the area – was suspected of also injuring 13 people during a shooting rampage at a bowling alley and bar on Wednesday night in Lewiston. Card died of an apparent self-inflicted gunshot wound, authorities said.

Jim Ferguson, the ATF special agent in charge in Boston, said the weapons used in the shooting had been purchased legally. Many firearms were recovered from Card although he declined to say their make, model or how many exactly.

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

At the Saturday press conference, Sauschuck said Card had a history of mental illness, but there was no evidence that he had ever been involuntarily committed. “Just because there appears to be a mental health nexus to this scenario, the vast majority of people with mental health diagnoses will never hurt anybody,” he said.

As for why Card chose his targets, Sauschuck said it was likely due to paranoia, that he thought people were talking about him.

He also said the note found in Card’s home was meant for a loved one with the password to his phone and bank accounts. Sauschuck said he wouldn’t describe it as an explicit suicide note but that the tone indicated that was the intent.

Street life returned to normal in Lewiston on Saturday morning after a days-long lockdown in the city of 37,000. Joggers took advantage of the warm weather. People walked dogs through downtown and picked up coffees and visited other shops that had been closed since the shooting. (AP)