By Steve Gorman
LOS ANGELES (Reuters) - A lone suspect has been arrested and charged with four counts of murder in the slaying of a couple and their two young sons whose skeletal remains were found buried last year in the California desert, police and prosecutors said on Friday.
The accused, Charles "Chase" Merritt, was described as a business associate of the father, Joseph McStay, whose family was reported missing in February 2010 from their Southern California home, San Bernardino County Sheriff John McMahon said.
Merritt, 57, was arrested without incident on Wednesday, and investigators have no evidence to suggest any other suspects, McMahon said. He declined to discuss possible motives for the killings.
Autopsies determined the four victims - McStay, 40, his wife, Summer, 43, and their two boys, 4-year-old Gianni and 3-year-old Joseph - died of blunt-force trauma, the sheriff said. Investigators believe they were killed at their home in the San Diego County community of Fallbrook.
San Bernardino County authorities took over the investigation last year after the remains were found in the desert near Victorville, about 70 miles northeast of Los Angeles.
County prosecutor Michael Ramos said Merritt is eligible for the death penalty if convicted.
"This is a cold and callous murder of an entire family," Ramos said. "There's no reason, no motive ... for that ever to occur, especially for the young children, the most vulnerable victims."
Video footage posted online by the sheriff's office showed the gray-bearded Merritt, his hands shackled to his waist, being escorted by officers from a patrol car to the detention facility where he was booked on four counts of murder.
He was being held without bond and was due to make his first court appearance later Friday in Victorville.
McMahon said his department's yearlong investigation involved 60 search warrants and more than 200 interviews.
(Reporting by Steve Gorman; Editing by Cynthia Johnston and Jim Loney)