LANSING, Mich. (NewsNation) — Police continue to search for a motive in the Michigan State University shooting that left three students dead and five other students injured when a gunman opened fire in two academic buildings on the Lansing campus.

Michigan State University Police identified two of the three victims as sophomore Brian Fraser of Grosse Pointe and junior Alexandria Verner of Clawson.

Dr. Jon Dean, the superintendent of Grosse Pointe North High School, identified the third victim to NewsNation as 2021 graduate Arielle Diamond Anderson.

MSU Police Interim Deputy Chief Chris Rozman identified the suspect as 43-year-old Anthony Dwayne McRae, who has no known ties to the university.

McRae, described as a Black man wearing red shoes, a jean jacket and a baseball cap, was found dead at approximately 11:35 p.m. ET Monday from a self-inflicted gunshot wound off-campus in the city of Lansing hours after the shooting began, Rozman said. Shortly after the suspect’s picture was released to the public, a caller’s tip helped identify him.

McRae’s father, Michael McRae, told NBC News on Tuesday that Anthony became bitter after his mother died of a stroke in 2020, and that he “didn’t care about anything anymore.”

McRae had a previous misdemeanor conviction for possessing a loaded firearm in a vehicle in 2019 and two misdemeanors in 2006 for driving with a suspended license, according to state police records. He spent a year and a half on probation for the firearm conviction, which ended in the spring of 2021.

The MSU Department of Police and Public Safety confirmed that police found a note on the suspect when they discovered his body, and that the note is currently being investigated by law enforcement.

The note in his pocket indicated a threat to two schools in Ewing Township, New Jersey, where he had ties, according to a statement by the Ewing Police Department.

The five injured MSU students transported to Sparrow Hospital remained in critical condition Tuesday morning, some with life-threatening injuries. Four of the five patients required surgical care, Interim President of E.W. Sparrow Hospital Dr. Denny Martin said.

“It’s too early on in their course to give any kind of prognosis at this point,” Martin said.

The shooting began at 8:18 p.m. ET Monday at Berkey Hall, Rozman said. The police response was “overwhelming” and officers arrived within minutes.

East Lansing Mayor Ron Bacon said that the community was accustomed to responding to large-scale events and have been trained to respond in a coordinated manner.

Two MSU students were found dead at Berkey Hall, along with some injured students who were transported to the hospital.

Police then received reports of a shooting at the student union building, which is adjacent to Berkey Hall. A third victim was found dead at the student union building, Rozman said. Berkey and the student union were the only buildings where shootings occurred.

Rozman said no threats had been made against the campus in the days preceding the attack.

“Many of us have gone through the grim exercise of figuring out who our last call would be to,” Michigan Gov. Gretchen Whitmer said. “Last night, a lot of kids on this campus made those calls. They worried for their lives and for their friends.”

Rep. Elissa Slotkin (D-Mich.) said she can’t believe she’s doing another press conference for another school shooting just 15 months after the Oxford High School shooting where 15-year-old Ethan Crumbley killed four students in Oxford Township, Michigan.

“I cannot believe that I am here again doing this 15 months later,” she said. “I am filled with rage that we have to have another press conference to talk about our children being killed in their schools.”

“But for me, the most haunting picture of last night was watching the cameras pan thru the crowds and seeing a young person wearing an ‘Oxford Strong’ sweatshirt. The sweatshirts that were handed out after those kids lived through a school shooting 15 months ago and we have children in Michigan living through their second school shooting in under a year and a half,” Slotkin continued.

President Joe Biden released a statement, offering prayers and condolences to the families that lost students Monday night but also demanding that Congress take action.

“The fact that this shooting took place the night before this country marks five years since the deadly shooting at Marjory Stoneman Douglas High School in Parkland, Florida, should cause every American to exclaim ‘enough’ and demand that Congress take action,” the statement said.

Michigan State University President Teresa Woodruff said resources will be available to students and faculty at the Hannah Center to help them through this time.

All campus activities were canceled for the next 48 hours as police continue to investigate, police said.

The FBI and MSU police have asked people to share any videos or images of the active shooter incident with them to help with the investigation.