Police say Jennifer Hart had a blood alcohol level of 0.10, which is over the legal limit, when killing her family.
Toxicology tests also found that her wife Sarah Hart and two of their children had "a significant amount" of an ingredient commonly found in the allergy drug Benadryl, which can make people sleepy. Toxicology results on a third child whose body was recovered from the crash area are still pending.
CrimeOnline will provide additional updates when more information is available.
Authorities did not elaborate on items that were found in the river this week, but said that a vehicle seen going into the river on April 6, when a massive storm swamped areas of Northern California.
The 31-metre drop killed the women, both 39, and their children Markis Hart, 19; Jeremiah Hart, 14; and Abigail Hart, 14. Debris at the accident site and other material found along the riverbanks also was consistent with that vehicle, officials have said.
Efforts to find the three missing Hart children are continuing.
In new book, Comey says Trump is 'untethered to truth'
The Republican National Committee launched a website called lyincomey.com, outlining Democrats' previous criticisms of Comey. Bush administration, he was appointed by President Barack Obama to lead the Federal Bureau of Investigation in 2013.
Authorities said that a vehicle, which witnesses identified as possibly a Honda Pilot SUV, vanished after falling into the rain-swollen Eel River in Mendocino County around 1 p.m. Friday.
Four members of the Thottapilly family, including a man and wife and two children, went missing this month while traveling from Portland, Oregon, to their home in the Los Angeles suburb of Santa Clarita. Hannah Hart, 16; Devonte Hart, 15; and Sierra Hart, 12, have not been found. The crash happened just days after authorities in Washington state opened an investigation following allegations the children were being neglected.
Parts of a vehicle consistent with a Honda were found, as well as "various personal items that were consistent with a family traveling on vacation", according to a news release from the California Highway Patrol.
Last August, soon after the Harts moved into their rural home, neighbors Bruce and Dana DeKalb said a child rang their doorbell, seeking sanctuary from abuse.
Long before the crash, Sarah Hart pleaded guilty in 2011 to a domestic assault charge in Minnesota over what she said was a spanking given to one of her children. Then, in March, one of the Hart children began asking the DeKalbs for food, and claimed his mothers were withholding food.