Video from Michigan School Shows Students Escaping Classroom After Shots Rang Out

Update: Authorities have said the person with whom students were interacting on the other side of a locked classroom door was a member of law enforcement and not the suspect.

Additionally, authorities said Wednesday afternoon that a fourth victim, 17-year-old Justin Shilling, has died.

Student-filmed footage from inside Oxford High School on Tuesday shows a group of teens escaping a classroom through a window after interacting with someone on the other side of the room's locked door — someone they believed might be the shooter.

In the harrowing video, posted to Snapchat, students huddled on the floor whisper to each other as a voice comes from behind the room's closed door.

"Sheriff's office," the voice says. "It's safe to come out."

A male student replies that the students inside are unwilling to open the door.

"We're not willing to take that risk now," the student says.

The voice on the other side says "I can't hear you."

When the male student repeats that the risk is too great, the voice says something that seems to generate suspicion.

"Okay, well, open the door, and look at my badge, bro," the voice says.

"He said 'bro,'" another student says, as they all get to their feet. "Red flag."

The students, possibly believing the voice on the other side of the door is the shooter, race towards a window, and rush outside, running across snow and ice to another school building, where law enforcement assures them they're safe.

It has not been confirmed if the person speaking to the students through the door was, in fact, the shooter.

Three students were killed in Thursday's shooting, which injured eight other people.

Calls to 911 about the shooting came in at 12:51 p.m., police have said. Within five minutes, the suspect had been apprehended. He surrendered without incident and was not injured.

Oxford is located 30 miles north of Detroit.

The three people killed were identified as Tate Myre, 16; Hana St. Juliana, 14; and Madisyn Baldwin, 17.

Tate died in a sheriff's patrol car as he was being rushed to a hospital.

Of the eight injured people, seven were students ranging in age from 14 to 17, and one was a 47-year-old teacher.

Three students are listed in critical condition, including a 15-year-old boy who sustained a gunshot wound to the head and a 14-year-old girl who was struck in the the neck and chest.

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The teacher, who was shot in the shoulder, has been released from the hospital.

At this point, the teen suspect has not been formally charged with any crime. The teen has refused to talk with investigators.

He is being held at Oakland County Children's Village, a juvenile detention facility, and was placed on suicide watch.

Officials said Tuesday night that the gun used in Tuesday's mass shooting had been recovered from the suspect, and that it still had seven bullets in its chamber. Authorities have said the suspect's father purchased the gun four days before the shooting.