ATLANTA -- Lynn Turner, who was convicted in 2007 of killing her husband and boyfriend with antifreeze, has died in prison.

Officials said Turner, 42, died in Metro State Prison in Atlanta on Monday.

A release from corrections officials said Turner was found in her cell at 6:55 a.m. Monday and that prison medical staff and EMS crews were unable to revive her.

The cause of death is under investigation by the GBI Medical Examiner's office.

The trial found that Turner murdered her husband, Cobb County police officer Maurice Turner in 1995, and in 2001, killed her boyfriend, Forsyth County firefighter Randy Thompson -- both by poisoning with antifreeze.

She was serving a life sentence for Thompson's murder.