A man accused of killing his parents Friday at a residence hall at Central Michigan University has been arrested, campus officials said.
James Eric Davis Jr., 19, was identified as a suspect in what authorities said was a family-related domestic dispute. It was the nation's 12th school shooting this year.
Davis was arrested early Saturday after someone on a train passing through the north end of campus spotted him, the university said in a statement.
"CMU President George E. Ross thanks the campus and surrounding community and many law enforcement personnel who came together to keep each other safe and apprehend the suspect," the statement said.
He was arrested without incident.
The university, in Mount Pleasant, identified the victims as James Eric Davis Sr., 48, and Diva Jeenen Davis, 47, the suspect's parents.
A relative told CNN: "The family is in shock and trying to piece everything together."
Campus police spoke with James Davis Jr. on Thursday night, Lt. Larry Klaus with CMU Police said during a news conference.
"At some point in the evening he was transported to McLaren Hospital due to what the officers believed may be a drug-related type incident, an overdose or a bad reaction to drugs. At that point he was released to the hospital staff," Klaus said.
As for Friday's shooting, "we're calling it a family-type domestic issue at this point," Klaus said.
The shooting happened about 8:30 a.m. Friday on the dorm's fourth floor.
The victims were from the Chicago suburb of Bellwood where James Davis Sr. was a part-time police officer for 20 years who assisted the department on special occasions.
"He was always there when you asked for him to be there," Bellwood Police Chief Jiminez Allen said.
Bellwood Mayor Andre Harvey said he thought the parents were picking up their son before spring break.
James Davis Sr. was a pillar of the community, which has 20,000 residents, and was beloved by friends and neighbors, the mayor said.
The violence came more than two weeks after a shooting rampage at Marjory Stoneman Douglas High School in Parkland, Florida, left 17 people dead and spurred a national debate over gun control.
Schools in Mount Pleasant went into "secure mode" -- meaning all interior doors were locked, blinds drawn and no one allowed to enter buildings, according to Jennifer Verleger, Mount Pleasant Public Schools superintendent
The men's basketball game Friday between Central Michigan and Western Michigan University was postponed, said Michael Alford, Central Michigan's athletics director.
President Donald Trump was briefed on the shooting, according to White House deputy press secretary Hogan Gidley.
The Mount Pleasant police and Isabella County Sheriff's Department were assisting university police, officials said.
Agents from the Bureau of Alcohol, Tobacco, Firearms and Explosives also assisted in the investigation, according to an ATF tweet.
The university, with roughly 23,000 students, is about two hours northwest of Detroit.
CNN's calculation of the number of school shootings include shootings on school property, that involve one of more victims, includes domestic violence incidents, and other factors.