A jury deliberated nearly eight hours Friday before convicting a teenager of setting a fire that killed an elderly couple in their south Oklahoma City home.
Jurors found Tristan Owen, 17, guilty of two counts of manslaughter in the first degree and one count of arson in the first degree.
Panel members, though, could not agree to convict Owen of first-degree murder.
If they had, Owen would have been sentenced as an adult for killing Boyd Haynes, 87, and his wife, Doris Haynes, 86, and could have spent the rest of his life in prison.
Instead, Owen faces up to 18 years in prison after jurors recommended four years on each of the manslaughter counts and 10 years for the arson count.
Owen is set to be sentenced June 14.
The couple died of smoke inhalation, July 13, 2011, a few hours before they were scheduled to move into an assisted-living facility.
Members of the victim's family appeared disappointed when the verdicts were read and left the courtroom without speaking to reporters.
Owen's family also declined to comment.
Prosecutors alleged Owen, then 15, started a fire in a trash container outside the couple's garage, which spread to the structure.
Neither arson investigator who testified, however, could link burned pajama pants found on the defendant's property and remnants of two Molotov cocktails found in front of his house with the trash can fire.