California drivers are considered drunk with a level of 0.08 or higher.
"Sarah Hart and two of the children had a positive toxicology finding in their blood for Diphenhydramine, an active ingredient in Benadryl", it said. It has not been determined in the third child.
On April 8, the relatives in San Jose contacted the police department and officially reported the family missing, telling the authorities that the family had been traveling from Portland. A specialized team of accident investigators is trying to figure that out with help from the FBI, Carpenter said.
Search teams found debris and personal effects identified as belonging to the Thottapilly family on Thursday.
Devonte, 15, Hannah, 16, and Sierra, 12, remain missing.
Sheriff Tom Allman said in a television interview earlier this month that Jennifer Hart "is the woman that we believe was driving the vehicle when it crashed".
No skid marks were seen in the area, officials said.
"It appears she (Hart) was about 70 feet from the edge and accelerated from there", Carpenter said.
"The body was found on exposed terrain which appeared to have covered by the Eel River within the last few days as a result of a recent weather storm which brought heavy rain to the area".
It said several items were identified by the family members of those missing.
The Harts moved to a home in Woodland, Washington, in mid-2017, neighbors said. Were the children purposely drugged and did the parents know they were on suicide mission when they headed out for the "road trip".
He called Child Protective Services on March 23, and officials arrived just after Jennifer Hart came home from work, but she didn't answer the door.
Jennifer and Sarah Hart, both 39, and three of their adopted children, Markis Hart, 19; Jeremiah Hart, 14; and Abigail Hart, 14, have all been reported dead.
In 2010, Sarah Hart pleaded guilty to misdemeanor domestic assault involving one of the children, according to Douglas County, Minnesota, court records.
In the latest case, the Thottapilly family had taken a road trip from their home in Santa Clarita, Calif., to OR for spring break.
Sandeep Thottapilly (42), his wife Soumya (38), and their children Siddhant (12) and Saachi (9), were in a maroon Honda Pilot with a California registration plate (7MMX138).