"So the main state police tactical team ultimately were the ones that located the body within one of those trailers," Sauschuck said during a media briefing.
At 7:45 p.m. (23:45 GMT) on Friday, Card's body was found on the property, which contains overflow trailers of recycled materials, belonging to the recycling center where he used to work.
The commissioner also confirmed earlier reports of a note being found in Card's residence, but stopped short of characterizing it as a suicide note.
"So this is a paper style note. I'm not going to read it to you verbatim but ... it's a note to a loved one saying that 'This is the passcode for my phone. This is the bank account numbers.' And I wouldn't describe it as an explicit suicide note, but the tone and tenor was that the individual was not going to be around and wanted to make sure that this loved one had access to his phone," Sauschuck said.
Maine authorities are presently working on gaining access to Card's phone and records, the commissioner added.
Late Wednesday, the 40-year-old gunman opened fire at a restaurant and a bowling alley in Lewiston, Maine, killed at least 18 people and injuring numerous individuals in the area. Earlier reports detailed that Card had previously threatened to carry out a mass shooting, and that he had been admitted to a mental health facility over the summer for a two-week period.
A motive for the shooting has yet to be determined amid an ongoing investigation into the the shooting.