By Rich McKay
(Reuters) - A family of eight known as the "Hart Tribe" died last year in a murder-suicide when their sports utility vehicle plunged off a 100-foot (30 m) cliff in northern California, a coroner's inquest said on Thursday.
The mystery over why the family from Washington state perished in March last year on a scenic cliffside highway, about 180 miles (290 kms) north of San Francisco, garnered national attention.
A 14-member jury ruled that the deaths were the result of a "murder-suicide", Mendocino County Sheriff-Coroner Thomas Allman told a press conference late Thursday after a two-day inquest.
"This was held so the truth can come out," he said. "We needed to know the facts of this case."
The eight family members - two women and their six adopted children - are believed to have been in the GMC Yukon in March 2018 when it accelerated to about 90 mph (144 kph) and drove over a cliff, authorities said.
The bodies of Jennifer Hart and her partner Sarah Margaret Hart, both 38, were found in the vehicle which landed upside down, police said.
The children were Markis, 19; Hannah, 16; Devonte, 15; Jeremiah, 14; Abigail, 14; and Ciera, 12.
The bodies of four children were later recovered. A fifth child was linked by DNA to human remains found in a shoe on the coast about one mile (1.6 km) north of the crash site.
The remains of Devonte have never been found, Allman said.
Devonte, an African-American, drew international attention in 2014 when he was photographed embracing a white police officer at a rally to protest the shooting of a black teenager in Ferguson, Missouri.
The two Hart women died by suicide, Allman said. The deaths of the six children were ruled to be murders.
There was no known motive, Allman said.
Jennifer Hart is thought to have driven the car off the cliff three days after child protective services in Washington state opened an investigation into allegations she and her partner had neglected or abused the children.
A police autopsy has shown that Jennifer Hart was legally drunk at the time of the crash.
Three children, along with Sarah Hart, tested positive for an ingredient commonly found in the allergy drug Benadryl, which can make people sleepy, the sheriff's office has said.
"The Hart family is hopefully resting in peace," Allman said in officially closing the case.
(Reporting by Rich McKay in Atlanta; editing by Darren Schuettler)