Maine Commissioner of Public Safety Michael Sauschuck confirmed that Card died from an apparent self-inflicted gunshot wound. He did not say when Card is believed to have shot himself or how long the body had been in the woods.
Card's body was reportedly located near a recycling center where he used to work. The area was within walking distance of the boat ramp where his vehicle was discovered.
Card is suspected of opening fire at a bowling alley and then, a few minutes later, at a restaurant a few miles away on Wednesday (October 25) night. The shootings left 18 people dead and 13 others injured.
After the shootings, a massive manhunt was launched as authorities searched frantically for Card, who is a member of the Army Reserve and a certified firearms instructor.
Police said he suffered from mental health issues and spent two weeks in a mental health facility over the summer after he threatened to shoot a National Guard base.
Sauschuck said that officials would provide more details during a press conference on Saturday morning.