Authorities believe the other two sets of remains are those of the McStays' sons, Joseph and Gianni, but those identities still need to be confirmed through DNA records, McMahon said. The manner of the deaths was homicide, he said.
Joseph McStay disappeared along with his wife, Summer, and their two young children, Gianni and Joey, in February 2010, launching what San Diego sheriff's investigators called their most extensive missing-persons search ever.
Investigators reportedly pursued hundreds of tips and eventually came to believe the family left voluntarily for Mexico. Investigators were convinced that four people seen on a dimly lit surveillance video walking into Tijuana, Mexico were the McStays.
Authorities announced Friday that remains found Wednesday in shallow graves near Victorville, about 60 miles northeast of Los Angeles, were those of 40-year-old Joseph McStay and his 43-year-old wife, Summer. Authorities said they believe the other remains belong to the McStay children, but they have more work to do to confirm it. Their deaths were determined to be homicides.
Autopsies were still being completed, and the cause of death has not been released.