WILLITS, CALIF. -- The final chapter of the investigation into a coastal California crash that killed a Southwest Washington family of eight begins Wednesday.

A special jury will convene in this rural town to hear evidence as part of Mendocino County’s first coroner’s inquest in more than fifty years. Eight investigators and one pathologist will testify about the yearlong quest to answer why Jennifer Hart drove the SUV carrying her family off the edge of a coastal cliff.

In the months and moments before they died, the family increasingly withdrew from the outside world. The parents did not stay in contact with relatives in the Midwest and lived in a rural home where they allowed no visitors. When investigators asked for witnesses to tell them about any sightings of the two white mothers and their six adopted black children during their three-state journey from home to the crash site, no one came forward.

The attorney who will oversee the inquest swore in eight women and six men as jurors Tuesday morning at the county courthouse in Ukiah, 20 miles south of downtown Willits, where the hearing will take place. Nearly all of the jurors said they had heard about the crash that turned the nation’s attention to their county.

By week’s end, officials expect the jurors will have determined the manners of death for Hart, 38, her wife, Sarah, also 38, and their six children, Markis, 19, Hannah, 16, Devonte, 15, Jeremiah, 14, Abigail, 14, and Sierra, 12.

“This just got into people’s minds of wanting answers,” said Mendocino County Sheriff Thomas Allman, who decided last year to convene the inquest to present evidence gathered by his detectives and other police agencies.

By presenting all the facts, Allman hopes to bring closure to the public, friends and family members -- both relatives of the Harts and the biological relatives of their children who lived their final hours in Mendocino County.

Reports of concern about the children’s wellbeing reached child abuse hotlines in Minnesota, Oregon and Washington in the years before they died.

Jennifer and Sarah Hart were living in Minnesota when they adopted their six children from foster care in Texas. The family eventually moved to West Linn and stayed there four years before buying a home in Woodland, Washington in 2017.

Although child welfare workers in Minnesota and Oregon found evidence to support claims of neglect, the children were never removed from the care of their parents.

After a case worker stopped by their Washington home to investigate another report of neglect, the Harts packed up their GMC Yukon and left.

The family drove south to the rolling mountains and sweeping coast line of Mendocino County. A security camera recorded Jennifer Hart in a store in Fort Bragg stocking up on groceries March 25, 2018.

The next day, a tourist spotted the family's wrecked SUV at the bottom of a cliffside lookout point north of Fort Bragg.

Mendocino County's panoramic views of the Pacific Ocean draw tourists to cliffside lookouts.

Allman happened to be on the coast that day at a sheriff’s substation a half-hour's drive from the crash site. He drove to the point after he heard dispatchers say multiple people were killed.

He watched as emergency responders gathered and rappelled down the cliff to the ocean's edge to retrieve bodies.

He took photos with his phone as he took in the scene. The photos captured clear skies and the wide expanse of the lookout.

"I was of the mindset that this was a terrible, horrible accident,” said Allman, referring to the first three days of the crash investigation.

This week, as he looked through the images on his phone one year later, Allman paused at two photos of the dirt parking lot. Allman estimated that 100 feet of land separate the cliff's edge from the road.

There were no skid marks.

There were no tire tracks to show Jennifer Hart had tried to break before driving her family over the edge. The realization was a turning point for the investigation, Allman said.

Allman had dual responsibilities to find out what happened. In California, sheriffs also serve as coroners.

His agency quickly discovered how difficult that would be. When he asked witnesses to contact the agency if they had seen the Harts as they covered the 570 miles from Washington to the California coast, no one stepped forward.

Investigators at Mendocino County alone spent more than 2,000 hours on the case, Allman said.

“There’s been a lot of tears shed over this case,” he said.

Troopers from California Highway Patrol and deputies from the family’s home county, Clark County, helped piece together the events leading up to the crash. Mendocino County detectives also tracked down the biological mother of the Hart’s oldest daughter, Hannah, after they found a foot months after the crash and believed it was hers.

"Every piece of evidence we got was just that much more shocking," said Undersheriff Matthew Kendall.

Allman decided to present the mounting evidence through a coroner's inquest after talking to another sheriff whose county convenes inquests often. By law, California sheriffs, in their role as coroners, can order inquests to take place.

Allman had planned to hold the proceedings last fall. County officials settled on one year after the crash in large part because middle son Devonte has still not been found. He is presumed dead.

“We know what the ocean takes, sometimes it doesn’t give back,” Kendall said.

Devonte gained international attention in 2014 after a photo of him embracing a Portland police officer went viral.

Allman believes that photo is one reason news of the family’s death has captured the public’s attention in a way that he has rarely seen. He compared the attention to just one other case in his 13 years leading the office. A 34-day search for a man suspected of killing two people in Fort Bragg ended when the man was shot and killed by authorities, Allman said.

Unlike then, the public interest has never ceased in the months after the crash. Online forums dedicated to discussing what happened still generate comments. Hart family friends from Minnesota camped in a half-dozen tents and combed the beach for remains months after the crash, Allman said.

County officials knew that no hearing room could fit the number of people looking for answers in the crash, so the they decided to livestream the inquest proceedings.

The county hired attorney Matthew Guichard to preside over the hearing and question investigators.

Guichard also oversaw Tuesday's jury selection process. He explained how inquests work and said that he had been involved with more than 100 of them.

Guichard recited the names of Jennifer Hart, Sarah Hart and each of their children.

He told jurors that it isn't their job to determine who may be criminally or civilly responsible for their deaths. Instead, the jury must conclude how each of the eight Hart family members died: by accident, by natural causes, by suicide or at the hand of another person.

"This is a formal coroner's inquest and it is a hearing designed to put out in the open the circumstances of the deaths of those eight individuals that I named to you."

Before swearing in the jury, Guichard asked the potential jurors if they heard about the case. Nearly all had. He said they must rely only on evidence "that comes in on the stand."

Guichard expects the proceedings will last through Friday.

The inquest will conclude after jurors determine what Allman should list as manner of death on each death certificate.

"I never intended to close the books on this until the facts are known," Allman said.

-- Molly Young

myoung@oregonian.com