Lyman Whitmore, 16, will spend 9-years-to-life behind bars for the December, 2007 murder of his 14-year-old nephew.
Dusty Elderkin's body was found submerged in nine feet of water in a creek along Bloomer Road in the Town of Stockton on December 15, 2007.
He was stabbed 40 times and beaten to death, said Chautauqua County District Attorney David Foley.
Whitmore, and an underage co-defendant who is being prosecuted in family court, went to Elderkin's home with a plan to kill the boy, Foley said.
"They coaxed Mr. Elderkin into leaving the trailer, and in between the trailer and a barn area, they repeatedly stabbed him and beat him to death," Foley said. "Following that, they took a wheelbarrow, tied two cement blocks around Mr. Elderkin's mid-section using outdoor electrical cord."
The boys pushed the wheelbarrow a quarter-mile down a dead end road and dumped the body.
Whitmore could have been sentenced to 15-years-to-life in prison, but received a reduced sentence after taking a plea just as the case was heading for trial last October.
Foley said a family dispute between the Whitmore and Elderkin led to the murder.