The speedometer in the car of a Woodland family who died in a crash on the California coastline was "pinned" at 90 mph, indicating to officers the vehicle was running and in motion just prior to hitting the rocks below, according to court documents.
A search warrant was served at the home of Jennifer Jean Hart and Sarah Margaret Hart on Thursday.
A search warrant affidavit was granted in Clark County in connection with this investigation for items including travel itinerary, bank records, cell phone records, credit card billing statements, bank receipts, notes, journals and possible suicide notes.
No details have been released about the results of the search at the couple's home. The couple purchased the home in May 2017 and previously lived in West Linn.
The Harts and at least three of their adopted children were killed after Jennifer Hart drove off a cliff near Highway 1 in the Westport area of Mendocino County on Monday, according to deputies.
Their three other adopted children were believed to be in the car, according to deputies, but they have not been located.
Court documents state California Highway Patrol investigators found no "acceleration marks, tire friction marks or braking furrow marks" at the scene.
Investigators said there was no evidence the car collided with the embankment as it "traversed towards the tidal zone below."
"Based upon the California Highway Patrol investigation, it is their belief 'a felony has been committed,'" according to court documents.
Neighbors in Woodland told FOX 12 this week they contacted Child Protective Services when one of the children, 15-year-old Devonte Hart, came to their home begging for food for himself and his siblings.
The Washington State Department of Social and Health Services released a statement Wednesday confirming a case was opened regarding the family last Friday, as "the now-deceased children were identified as potential victims of alleged abuse or neglect."