According to his father, the shooter who killed three people at Michigan State University had a history of mental illness and used to fabricate possession of a weapon.
After being prohibited from possessing firearms in the wake of a 2019 weapons violation, the father told US media that his son had hidden a gun in his room.
The suspect was discovered dead from a self-inflicted gunshot wound following the shooting spree on Monday night.
Arielle Anderson, Brian Fraser, and Alexandria Verner were the victims.
The attack inside the student union and an academic building also left five other people hurt.
Investigators say it's still unclear what motivated the shooter. He didn't seem to have any ties to the Michigan campus in East Lansing, which is 145 kilometers (90 miles) west of Detroit.
Anthony Dwayne McRae, 43, was the man who was identified by the police. He was accused of committing a felony in 2019 by being caught with a concealed weapon without a permit. .
He was spotted by a police officer in Lansing, Michigan, who asked if he was carrying a weapon after noticing him sitting outside an abandoned building.
The officer found the suspect's registered loaded semi-automatic pistol while performing a pat-down search.
He was placed on probation for an entire year and a half, during which time he was not allowed to possess a gun.
After the weapons charge, Michael McRae's son, who was living with him in Lansing, allegedly purchased a gun but refused to admit it to his father.
The father told the Washington Post, "He never let me in the room to show me the gun.". I would have thrown it away if he had shown it to me. ".
Even though there were bullet casings on the grass, the father claimed that when he heard gunfire in the backyard and confronted his son about it, he would tell him it was fireworks.
After the passing of his mother from a stroke in 2020, the father claimed that his son "began to change" and became resentful.
Mr. McRae observed, "He started to really let himself go.". His teeth were erupting. He gave up on shaving his head. He had a wolf man's appearance. ".
Mr. McRae told US media that he had tried taking his son to church and urged his son, who had trouble keeping a job, to visit a doctor.
On Tuesday, Debbie Dingell, a Democratic congresswoman from Michigan, echoed calls for red-flag laws made by other members of the state's legislature.
If someone is thought to be a danger to themselves or others, such legislation permits a court order to confiscate their firearms.
The incident happened the night before the fifth anniversary of the Parkland, Florida, school shooting, which left 17 people dead.