SOUTHFIELD, Mich. -

A 25-year-old man's death at Northland Mall has been ruled accidental position, compression, asphyxia, according to the Oakland County Medical Examiner's office.

McKenzie Cochran died Jan. 28 after a struggle with security at the mall, just north of Detroit. He was pepper-sprayed and restrained by guards after a jewelry store owner felt threatened and called for help.

Forensic pathologist Dr. Werner Spitz said pressure to Cochran's back while he was face down on the ground caused asphyxia.

"They put him face down on the ground, that is in prone position, face down, and then they applied pressure to his back and this led to his inability to breath, to expand his chest due to the pressure on him, and as a result of that he died," said Dr. Spitz.

Southfield Police Chief Eric Hawkins had said his department was investigating the use of force by the guards, but would not comment on specifics regarding what the verbal confrontation involving Cochran was.

No arrests have been made.

Cochran's family has hired an attorney. Gerald Thurswell said the guards were not properly trained or supervised. He's already filed a civil suit against the mall, the guards and the security company, asking for $800 million in damages.

But Teresa Cochran told Local 4 during an interview last month nothing is worth her son's life.

"To identify him from a photo is quite heartbreaking," said Teresa Cochran. "No parent wants to bury their children."

Watch interview: Mom speaks about son who died at mall

Video shows guards restraining a person who says he can't breathe. About 30 people held a protest at the mall demanding an explanation.

Southfield Mayor Brenda Lawrence said she wanted to make it clear that the case was not centered on race or any type of cover-up.

"We want it investigated. We want everyone to feel safe," she said.