The man accused of killing Naomi Irion, the 18-year-old who vanished in March 2022 from a Walmart parking lot in Nevada, has died by suicide, the Lyon County Sheriff's Office said in a news release.

Troy Driver, 43, "was in custody on murder charges and awaiting trial, for the murder of Naomi Irion," the release said. He was "in a maximum security jail cell and had no contact with other inmates."

Deputies tried to resuscitate Driver after finding him unresponsive Sunday afternoon during a routine inmate check, the sheriff's office said.

He'd been arrested shortly before Irion's body was found more than two weeks after she went missing. He'd been denied bail that April on the murder charge.

Irion last was seen before dawn March 12, 2022, in her car in the parking lot in rural Fernley, Nevada, authorities have said. She was waiting there to take a shuttle to work, her sister has said.

Surveillance video shows a man in a gray hooded sweatshirt approach Irion's car at 5:24 a.m., about a minute before the vehicle was seen leaving the parking lot with the man driving, Detective Erik Kusmerz said days later in a news conference. The car was found near the Walmart three days later.

Driver kidnapped and shot Irion, then buried her body in an attempt to conceal his crime, according to an amended criminal complaint filed in the Justice Court of Canal Township in Lyon County. He was charged with murder, first-degree kidnapping, robbery, burglary of a motor vehicle and destruction of evidence, it states.

Irion's body was recovered in a remote part of neighboring Churchill County by authorities acting on a tip, they have said.