Newly obtained adoption records have provided a lead in the search for the biological relatives of one of two children who remain missing after the rest of their family was killed in an apparent murder-suicide earlier this year.

Hannah Hart, 16, and Devonte Hart, 15, remain missing after their adoptive parents Jennifer and Sarah Hart and adopted siblings Markis, Ciera, Jeremiah, and Abigail were found dead at the site of a fatal SUV plunge in northern California in late March. As CrimeOnline previously reported, authorities believe that Jennifer Hart, who was legally drunk at the time of the crash, intentionally drove her family off a cliff along the Pacific Coast Highway in Mendocino County.

A confidential source has obtained and provided CrimeOnline with a partial document that appears to be the adoption petition submitted by Jennifer and Sarah Hart in Douglas County, Minnesota, to adopt Markis, Abigail, and Hannah Hart.

The document, dated March 4, 2006, lists the birth names of all three children and their counties of birth. The three biological siblings were adopted from foster care in Texas, and until this time their surnames at birth had not been reported. CrimeOnline has chosen not to publish the names at this time, but can report that the three children did not share the same surname.

As previously reported, the Mendocino County Sheriff’s Office has told CrimeOnline that they are working with Texas authorities to identify and locate biological relatives of Hannah Hart, to help identify remains found in early May about a mile from the crash site. A coroner has yet been unable to identify the remains, and could not conclusively determine through a DNA sample comparison if the unidentified remains belong to a biological relative of the deceased members of the Hart family.

CrimeOnline alerted the Mendocino County Sheriff’s Office about the information obtained from the adoption petition. We were unable to determine if the sheriff’s office had previous knowledge of the birth names of Hannah Hart and her two siblings.

On Friday, Mendocino County Sheriff Tom Allman provided CrimeOnline with the latest on the investigation, saying that he was on his way to the crash site when we reached him by phone, as he visits the scene every two weeks.

“In no way should anybody make an assumption that we have stopped investigating this case,” Sheriff Allman said, adding that his office is continuing to explore several avenues and that they are “making positive steps in the investigation every week.”

Despite earlier assurances from a sheriff’s deputy that the department had not concluded the missing children had died in the crash, on Friday Sheriff Allman indicated that authorities may be leaning further towards a determination that Hannah and Devonte Hart were in the SUV at the time of the fatal crash — while insisting that investigation is active and ongoing.

“As of today I have not seen any physical evidence that would lead me to believe that they did not perish with the rest of the family,” Sheriff Allman said.

He also said that authorities have not located any further physical evidence connected to the crash since a local resident found girl’s clothing and the partial skeletal remains of a foot inside of a shoe in early May. That resident gave the clothing and the shoe to a person who she knew to be a friend of the Hart family who had come to search the area. That person, upon seeing that the shoe contained skeletal remains of a foot, handed over the evidence to authorities.

Sheriff Allman said that his office is hoping to hold a public hearing on or around the one-year anniversary of the fatal crash, to discuss releasing all the evidence to the public. The sheriff said he hopes releasing more information about the investigation will “allow the conversation on a national level to continue regarding the oversight or lack thereof of foster and adopted children that move from the place of the original adoption.”

Jennifer and Sarah Hart moved their family twice in the last five years of their life, and began homeschooling their children immediately after Sarah Hart pleaded guilty to misdemeanor domestic abuse of one of her daughters in 2011.

“I’ve been in law enforcement for 35 years and I think that the possibility increases of being a victim of a crime when you move into an area and nobody knows who you are or where you came from,” Sheriff Allman said. 

“We have so many social services organizations throughout our nation … it would not be unreasonable to do some checks and balances.”