Argyropoulos said she contacted Oregon's Department of Human Services in July 2013 after being alarmed by the parents' treatment of their children during two visits the Hart family, which was then living in West Linn, made to her Bay Area home.
Beginning in 2008, Sarah and Jennifer Hart faced repeated child abuse allegations from teachers and neighbors as they moved from Minnesota to OR to Washington with their six adopted children.
The family's demise in late March came just days after child welfare authorities in their home state of Washington opened an inquiry into allegations that the children were being abused or neglected, according to police and social services agencies. He said his parents were not feeding him and his siblings, which prompted the neighbors to call state authorities, according to records and interviews.
He said examiners also found traces of an over-the-counter antihistamine that can cause drowsiness in the systems of the wife and two children.
Five people have been confirmed dead after the SUV carrying Jennifer Hart, her wife, Sarah, and and at least three children plunged from a 150-foot cliff in Northern California onto the oceanside rocks below last month.
When asked if it appeared whether Sarah Hart and the children were "knocked out" by the ingredient, Carpenter said he was not going to speculate.
Lead researcher Megan Bell said the children of convicted adults had a greater incidence of lower education levels, unemployment, substance abuse and unstable relationships, even when sociodemographic risk factors were taken into account. The bodies of the three eldest children have been recovered, while a body recovered last week is believed to be one of the three other missing children.
"Because fo the time in the ocean, the facial features were not there to allow the [biological] family to identify", Allman said.
The crash scene, about 200 miles (322 km) north of San Francisco, was discovered by a passing motorist on March 26. Officials found no skid marks to indicate sudden acceleration or braking, according to a search-warrant affidavit.
The former friend said authorities told her the children had been interviewed and were likely coached in their responses.
In 2013, a former friend of the Hart family told child welfare officials in OR in 2013 that Jennifer and Sarah Hart deprived the kids of food as punishment. Cheryl Hart said she hadn't been able to reach Sarah or Jennifer after receiving the text message.
The Mendocino County Sheriff, in conjunction with the Mendicino County Coroner's office, said during a Friday news conference that the body of an adult female was recovered about seven miles south of where the Valencia family's vehicle is believed to have gone off an embankment.
In this Tuesday, Nov. 25, 2014 photo, Portland police Sgt. Bret Barnum, left, and Devonte Hart, 12, hug at a rally in Portland, Oregon.
On the second trip, Jennifer Hart and the six children stayed for two weeks without Sarah.