A 17-year-old girl testified Friday she "just prayed" and covered her head during Ethan Crumbley's mass shooting at Michigan's Oxford High School, which left four students dead and seven others wounded in 2021.

"I didn't know if those were my last moments," Heidi Allen said during a hearing to determine if Crumbley should spend the rest of his life in prison without the possibility of parole.

As Allen recalled the horrific day she helped save a wounded classmate, Crumbley -- in an orange jumpsuit -- stared down at the defense table from behind his black-rimmed glasses.

Allen testified that she was turning a corner in a school corridor when she saw the shooter emerge from a restroom. He was dressed in black, with a hat and mask, but Allen said she still knew who he was. They had attended school together since middle school, she said.

"A million things went through my head at that point but I knew exactly who it was. But, at the same time, I just thought there's no way that could be him," Allen testified.

"Everything kind of slowed down for me," she said, adding that she covered her head and dropped to the floor.

"It was very quiet. There was no screaming, nothing. It was just the gunshots."

Allen sensed the shooter was approaching her.

"I just closed my eyes and eventually I realized he was gone," she said calmly during her testimony while several family members of victims cried in the courtroom.

Two female students near her were on the floor. Another girl in the hallway was also down.

"I asked everybody in the hallway from where I was if anybody had been hit," Allen testified. "And nobody had answered because they couldn't."

No one except Phoebe Arthur, who had been standing with her boyfriend. Arthur was crying. Allen helped her up and looked for an open classroom. Once inside, Allen put the night lock on the door.

"How did you know how to install the night lock?" a prosecutor asked.

"We have drills every year since middle school," Allen said.

At a drill just a month before the shooting, a teacher called on Allen to install the night lock on the door.

"I didn't know how to do it," she said. "I couldn't figure it out. She came over and she showed me exactly how to do it. When that moment came, I knew exactly how to do it."

Allen testified that she took Arthur to the middle of the classroom. There was blood everywhere. Arthur had been shot in the chest and neck. Allen used a sweater to apply pressure on her wounds.

Allen prayed with her classmate. She recalled thinking she was meant to be left unscathed in the hallway.

"I asked her if she knew who God was and she had said, 'Not really.' But I said, 'I think I'm supposed to be here right now because there's no other reason that I'm okay, that I'm in this hallway, completely untouched.'"

Arthur survived. Allen later turned Arthur's back to the carnage as they left the classroom to spare her from reliving the horror.

'I am going to be the next school shooter'

The testimony comes one day after tense exchanges between a shooting victim and the defense attorney cross-examining her and following the introduction by prosecutors of audio from two video clips Crumbley recorded before the rampage he carried out at his high school when he was 15 years old.

"My name is Ethan Crumbley, age 15, and I am going to be the next school shooter," he is heard saying on the audio that was played in court. "I've thought about this a lot. I can't stop thinking about it. But it's constantly in my head."

Crumbley appeared to look down at the defense table as the audio was played.

In the second audio file played at the hearing, Crumbley said, "I'm gonna have so much fun tomorrow."

During the recordings, Crumbley talked about the decline of his life and calmly laid out his deadly plan.

"I will walk behind someone, and I will shoot a bullet into their skull. And that's the first victim," he said. "I'm gonna open fire on everyone in the hallway ... I will try to hit as many people as I can. I will reload, and I will find people hiding. I want to teach them a lesson of how they are wrong, of how they are being brainwashed."

Oakland County Prosecutor Karen McDonald told the court on Thursday Crumbley's premeditated approach ahead of the shooting and propensity for violence are among the reasons he should receive a life sentence.

Crumbley's attorney, Paulette Loftin, said the defense will show Crumbley is not "irreparably corrupt" and should be sentenced to a term of years in prison.

The first prosecution witness was Lt. Timothy Willis with the Oakland County Sheriff's Office, who oversaw the shooting investigation. He testified that Crumbley bypassed device security and accessed a violent website on a jail computer tablet in January.

When authorities discovered the search history, which Crumbley had attempted to delete from the device, the teen said he could not "resist" visiting the site he'd frequented before the shooting, according to the lieutenant.

Prosecutor Marc Keast went over a handwritten journal with Willis that was recovered from Crumbley's backpack in a school bathroom after the shooting, highlighting excerpts about his plans, which were written weeks and months before the carnage.

Crumbley successfully executed many of the plans he outlined in the journal, Keast told the court.

One entry said: "I want to shoot up the school so f**king badly."

"The first victim has to be a pretty girl with a future so she can suffer just like me," Crumbley wrote in another.

The first shooting victim was Arthur, the lieutenant confirmed.

"I will continue shooting people until police breach the building," Crumbley wrote. "I will then surrender to them and plead guilty to life in prison."

Crumbley pleaded guilty in October to one count of terrorism causing death, four counts of first-degree murder and 19 other charges stemming from the mass shooting.

In the week before he killed his schoolmates, Crumbley Googled a series of questions about the death penalty and prison sentences for 15-year-olds in Michigan.

On cross-examination of Lt. Willis, Loftin read entries from the shooter's journal where he expressed wanting help to stop his negative feelings.

"All one of my teachers has to do is send me to the office and ... I can get help," Crumbley wrote.

"One call and that can save a lot of lives. My evil has fully taken over in me and I used to like it, but now I don't want to be evil. I want help but my parents don't listen to me so I can't get any help. I feel like I'm in a tiny loop of sadness."

On Thursday afternoon, Molly Darnell, who at the time was an educator at the school, testified that she locked eyes with Crumbley through a glass window before he raised and pointed his pistol at her.

Darnell said she was attempting to put on a safety mechanism to lock down a door when she suddenly jumped to the right. A bullet pierced and passed through her left arm. She realized months later the bullet likely would've struck her heart had she not reacted.

Darnell texted her husband, "I love you. Active shooter," she testified.

As an adult, Crumbley would be sentenced to life in prison without parole, the harshest punishment under Michigan law. Because he's a minor, the court needs to hold a hearing to consider whether he should have a chance for eventual release.

Prosecutors argue Crumbley deserves a life sentence without parole. Crumbley's lawyers will present mitigating factors, including his age, home life and the possibility he can be rehabilitated, to argue that life without parole is disproportionate.