SANTA FE, N.M., Oct. 9 (UPI) -- A young man who killed his family at age 14 on a ranch owned by Sam Donaldson has been freed, New Mexico authorities said Saturday.

Cody Posey confessed to shooting his father, Paul Posey, 34, stepmother, Tryome Posey, 44, and stepsister, Mairlea Schmid, 13, on July 5, 2004, and using a backhoe to bury their bodies in a manure pile, CNN reported.

Donaldson, the former ABC newsman, found the crime scene.

The teen, who said he snapped after years of physical and psychological abuse, was convicted in February 2006 of voluntary manslaughter of his father, second-degree murder of stepmother and first-degree murder of his stepsister.

The state wanted the maximum adult sentence, life without parole. But the judge decided Posey could be rehabilitated and sentenced him as a juvenile. He turned 21 Saturday, could no longer be held as a juvenile and was free to go.

While in custody, Posey obtained his high school degree and completed nearly two years worth of college credits, said his uncle, Carl Clees.

[Emphasis added] Posey's defense called 40 witnesses, including ranch hands who said they witnessed years of physical and psychological abuse by the father.