Mystery of McStay Family's Disappearance Ends With Arrest Today

— -- A business associate of a California family that mysteriously disappeared more than four years has been charged in the four murders - including two young boys, police said today.

The remains of Joseph and Summer McStay and their sons were found in the desert near the U.S.-Mexico border last year, reinvigorating the investigation and today San Bernardino County authorities announced that they made an arrest in the case.

Charles"Chase" Merritt, who knew the family through business, has been charged with all four murders and is expected to appear in court later today, the Associated Press reports.

No cause of death has been released, but the San Bernardino County Sheriff's office says that all the victims died of blunt force trauma.

The remains of Joseph McStay, 40, and his wife, Summer McStay, 43, along with their two young sons Gianni McStay, age 4 and Joseph, age 3, were found in early November 2013. When the bodies were found, the sheriff said they were otherwise intact and clothes were found in the graves, although he declined to elaborate about what items were found.

The parents and their sons, ages 3 and 4, vanished from their San Diego home in February 2010,but there were no signs of forced entry. There were signs -- rotting eggs on the kitchen counter and two pets in the backyard-- that the family left suddenly. Their car was found parked near the border off Interstate 15.

The sheriff's office reported that investigators have issued 60 search warrants and conducted more than 200 interviews in the past year since the bodies were found.

Joseph's father, Patrick McStay, told ABC News in 2010 that his son owned a company that designed interior decorative fountains and had done business in Tijuana as recent as a few months before his disappearance.

Investigators initially suspected that the family's abrupt departure was voluntary and that they had gone to Mexico for some unexplained reason. They even cited surveillance video of a family of four crossing the border on foot several days after they were reported missing and said they believed that family was the McStays.

The Associated Press and Alyssa Newcomb contributed to this report.