Sgt. Michael Baylous, State Police spokesman, said troopers were relieved Belknap admitted his guilt, especially in the deaths of the children.
"Now we won't have to put the witnesses, troopers and other first responders through the experience of a trial and make them relive those experiences," Baylous said. "Sgt. (D.A.) Evans today said the crime scene was just horrific. All of those who responded will never be able to get rid of that image.
"It's just seared into their minds forever. Nobody should have to witness that kind of scene," he said.
In 2006, Belknap's father, Kenneth Belknap, was sentenced in Nicholas County to life in prison with the possibility of parole for first-degree murder. James Belknap pleaded guilty to a drug conspiracy charge in the same case, and prosecutors dismissed a murder indictment against the son, according to court records.
An account of court testimony in The Register-Herald indicated the victim, Richard Parnell, was shot in a dispute over a cocaine deal and his body was then set on fire. Kenneth Belknap said his son had no involvement in Parnell's killing.
James Belknap was released from prison in 2009.
Baylous said troopers involved in the case would likely attend Belknap's sentencing, set for 3 p.m. on Aug. 28. Baylous said he's confident an appropriate sentence would be handed down.
He said it's good for troopers to attend a sentencing, as it has the power to strengthen their faith in the justice system.