Detail by detail, the 18-year-old from Saline Gave Judge Randy Tahvonen her account of what happened the night of February 15.
"I was contacted by Brendan Heim and Tyrel Bredernitz to be given a ride to East Lansing," said Samantha Grigg in her testimony.
Grigg said the plan was to rob 19-year-old MSU student Dustyn Frolka at his apartment. Instead, the three took Frolka to another location to get money.
"In the course of taking him home, Brendan began to punch him in the backseat of the car," she continued.
That's when, she says, Frolka opened the door and jumped out near the East Lansing exit on I-69.
"At that point, Tyrel and Brendan went outside of the car, took his clothing and his money and came back into the car," said Grigg.
The teen found out about Frolka's death later. Her guilty plea is part of a deal with the prosecutor, lowering her charges from Murder, Armed Robbery and Conspiracy to Armed Robbery.
They now stand at Manslaughter and Unarmed Robbery. Instead of life in prison, she now only faces up to 15 years. Grigg's attorney Ronald Zawacki says it's the right move.
"Her involvement was less than the other individuals," he said. "That's why she was offered the lesser charges."
Grigg is scheduled to appear back in court on May 27th for sentencing. As for the other two suspects, the prosecutor says their punishments will fit their crimes.
"We made an agreement with her because of her participation," said Clinton County Prosecutor Charles Sherman. "They're facing potential life without parole at this point."
When 16-year-old Brendan Heim and 18-year-old Tyrel Bredernitz do take the stand, it could be Grigg testifying against them.
"She would be obligated under this plea agreement to offer truthful testimony," said Zawacki.
Bredernitz is scheduled to make his plea, June 9. Heim is still being evaluated to see if he's fit to stand trial.