A Virginia woman whose son's remains were found in the trunk of her car more than 10 years after he was last seen alive pleaded guilty Friday in his death.

Tonya Slaton, 46, pleaded guilty to voluntary manslaughter in Hampton Circuit Court, records show. Slaton had previously faced a second-degree murder charge in connection with Quincy Davis' death and was set to go on trial Monday.

Quincy was last seen in 2004, around the time he was a middle-school student in Virginia Beach, the Virginian-Pilot reported. He was never reported missing and would be in his 20s today.

His body was discovered after a state trooper pulled Slaton over in 2015. Investigators estimate he had died about 10 years earlier, when he was 14 or 15.

The trooper who pulled Slaton over noticed a large white spot on the floorboard behind the driver's seat that Slaton said was from bleach, according to records in the case. When the trooper opened the trunk of the Ford Mustang, he found a black trash bag, the Daily Press reported, citing an affidavit for a search warrant.

Slaton told the trooper there were clothes inside, but he noticed a strong odor of rotting flesh coming from it, according to the affidavit. Quincy's remains were inside.

A medical examiner couldn't determine the boy's exact cause of death. On Friday, prosecutor Richard Shayegan said Quincy had a broken vertebra in his neck, according to the newspaper, which also reported that his body showed multiple injuries over time.

Slaton was sentenced to 10 years in prison, with two years suspended.

No one responded immediately to a message left with the Hampton public defender's office.