Police say Marcell Willis did not have any accomplices when he opened fire inside a Grand Forks, North Dakota Wal-Mart, but much of the circumstance surrounding the deadly May 26 shooting remain a mystery.
The investigation into the attack is officially closed, but the reason the 21-year-old U.S. Air Force airman killed one Wal-Mart worker and wounded another before taking his own life is still unknown, the Grand Forks Herald reports
The paper says police could find no connection between Willis – who was stationed at the nearby Grand Forks Air Force Base – and his victims.
The Grand Forks Police Department also released videos collected from the store's security cameras, which you can view by clicking here.
What do we know?
The airman, originally from Tennessee, was found to have been drunk during the attack – autopsy results showed his blood-alcohol level was twice North Dakota's legal limit at the time.
About two hours before opening fire at the store, Willis updated his Facebook account with the words "RIP TO ME LOVE EVERYONE."
According to Valley News Live, he drove to the Wal-Mart at about 1 a.m. with two friends, telling them he was there to pick up "another friend" before leaving the vehicle.
He did not return.
Instead, shots were fired inside the store, leaving Wal-Mart employee Lisa Braun with a gunshot wound to the shoulder, and her co-worker, 70-year-old Gregory Weiland, dead.
Willis died from a self-inflicted gunshot wound.