(CNN)A sixth member of the Hart family has been confirmed dead after the clan's SUV plunged off a Northern California cliff last month.
Hart family crash: Body ID'd as 12-year-old Ciera Hart
Investigators have identified 12-year-old Ciera Hart's body, leaving two children of the Washington state family missing.
Detectives have said those remaining children were believed to be in the SUV when it crashed onto a remote and rocky Mendocino County shoreline, and may have been swept away by Pacific Ocean waters.
The crash, which investigators say may have been intentional, left at least six people dead: The driver, Jennifer Hart, 38; her wife, Sarah Hart, 38; and four of their adopted children -- Markis, 19, Jeremiah, 14; Abigail, 14; and Ciera.
The two other adopted children -- Hannah, 16; and Devonte, 15 -- are missing.
The body that investigators now know was Ciera's was found in the surf on April 7, nearly two weeks after the other bodies were found in or near the vehicle on March 26.
Investigators suspected the body was linked to the crash, but it wasn't identified until Tuesday, when DNA test results came through, the sheriff's office said.
Sheriff Tom Allman has described the crash as "a crime." The vehicle appears to have left a highway for a dirt turnout, then accelerated on that turnout for about 70 feet until it went off the cliff, authorities said, citing data from the vehicle's software and air bag module.
Investigators haven't announced a possible motive. But the crash came as child protection personnel in the family's home city of Woodland, Washington, were trying to visit them after a neighbor said he reported a child's complaint of mistreatment.
Some of the children had repeatedly accused their mothers of abuse, according to reports from neighbors and a social worker.
Authorities have said the driver, Jennifer Hart, had a blood alcohol level above the legal limit for motorists.
Sarah Hart and two of the children found dead at the scene tested positive for diphenhydramine, an active ingredient in Benadryl, authorities said.
Diphenhydramine is an antihistamine that can cause drowsiness.
In 2014, Devonte garnered national attention when he embraced a white police officer at a time when racially charged protests were being held across the country following a grand jury's decision not to indict the white Missouri police officer who killed Michael Brown, an unarmed black man.
Devonte helped quell tensions with his sign offering "Free Hugs," and his photo was shared around the world.