Police Radio Reveals Terror and Confusion in Hunt for Michigan State Gunman

There were calls about gunfire coming from dorm rooms all across campus. Reports of shooting and screaming from a basketball court. Someone threatening five people with a firearm at an off-campus apartment.

The mass shooting at Michigan State University on Monday night left three students dead, five others seriously wounded and more than 50,000 locked down in terror for hours. As law enforcement conducted the manhunt, thousands of people across the campus in East Lansing, Mich. — and across the world — listened in, tuning into live feeds of the local police scanner.

The radio transmissions between officers, medics and dispatchers gave civilians a rare — and often terrifying — real-time window into the mass shooting response. They also laid bare an almost impossible task for even the most coordinated and fine-tuned of law enforcement responses: tracking down one man with a gun on an eight-square-mile campus filled with 400 buildings, decentralized closed-circuit TV cameras, and tens of thousands of petrified students and staff members, seeing signs of danger in every shadow.

Only later did it become clear that the threat stemmed from one source: a 43-year-old man wearing a jean jacket and red sneakers and carrying a handgun, who now appears to have left the university soon after opening fire in two buildings at the north edge of campus.

But none of that was known at the time by the public, or even by law enforcement, which was chasing down a deluge of 911 calls from across a campus filled with dead ends and false alarms.

The New York Times reviewed the radio traffic from the “Greater Lansing Area Public Safety” feed posted on Broadcastify, a website that provides public access to emergency radio communications. At one point, more than 240,000 people were listening to the feed on Monday night — a record amount of traffic on the website, according to its founder, Lindsay Blanton.

The Times used audio recordings that captured one batch of police radio traffic during the response. Most of the communications involve dispatch calls assigning officers to investigate a 911 report, often multiple 911 reports.

The Times’s analysis found that during the three hours after the gunman fled the shooting sites, law enforcement was dispatched to investigate at least 90 calls about suspicious activities or people across more than 50 other locations. Even reports that in hindsight seemed highly improbable had to be chased down.

Callers described a man wearing black jeans and a white shirt walking the halls of a dorm with an “AR” rifle, a white male in a black jacket carrying a paper bag, a Black male in a blue hat, a male in a red Stanford hoodie, possibly burgundy — or green.

There were many 911 calls about suspicious vehicles: a Ram truck circling over and over, a black pickup not moving, a gray truck heading into oncoming traffic. One 911 caller claimed that someone in a silver S.U.V. had shot at them. Another reported a person riding a child’s bicycle, carrying a bag, possibly with a gun sticking out.

“A lot of those calls sounded real when they went out. We thought they were real and we responded like they were real and we were ready to do what we’re trained to do,” Chris Rozman, the university’s interim deputy police chief, said at a news conference on Thursday.

The university police were scouring security footage to track down images of the gunman when reports about multiple shooters began to emerge from students and parents.

As time ticked by and the civilian audience on Broadcastify grew, a feedback loop of terror and confusion took hold among students, staff members and even law enforcement.

Occasionally it was police officers who called in suspicious activities over the radio. In a dorm, one officer reported a bathroom that smelled of gunpowder or fireworks. And in another, officers flagged a man running from them. “We just had a guy duck. We tried with a flashlight and he ran out the other way,” an officer told the police dispatcher.

At 9:26 p.m., about an hour after the shooting began, the university police department issued an alert about an active shooting at a sports facility: “There is another reported shooting at IM East. Police are responding,” it read. “There are multiple reported injuries.”

It turned out that there was no shooting or injuries.

“We asked our community to help us and report anything suspicious, and we appreciate each call that we received,” Mr. Rozman told The Times in an email. “At the time the calls were received we had no information that the shooter had left campus, and our priority at the time was to ensure the absolute safety of our students and campus.”

Reports about multiple shooters continued to proliferate, along with calls about explosives planted on campus.

At one point, a post from the moderator of a local radio hobbyist Facebook group warned members to stop writing about the scanner traffic because the shooter might be monitoring the page to evade law enforcement or plant disinformation. “There are almost 7k people in this group. We do not know if this person is in here,” the post read.

About three hours into the lockdown, the radio traffic shows similar suspicions were swirling at the law enforcement’s incident command. “Is it possible to secure an encrypted channel?” one officer asked the dispatcher, explaining that the publicly available feed was fueling concerns about “the scanner app being used by the suspect.”

The dispatcher warned that encrypting the channel would potentially prevent communication between officers from different agencies.

But minutes later, the concerns were suddenly dissipated by one 911 call that finally yielded the big break: A Lansing resident, nearly four miles from the university’s campus, spotted a man walking down the street wearing a jean jacket and red shoes.

Radio traffic captured reports from the officers dispatched to investigate. “We’ll try to make contact with him hopefully,” one officer said, while approaching the man. Seconds later, his voice returned. “Subject shot himself. We need medic here now.”

The authorities later announced that Anthony McRae died of a self-inflicted gunshot a few blocks from his house. The lockdown was lifted.

Aaron Byrd contributed video production.