The Tuolumne County District Attorney’s Office has asked the Superior Court to charge two 16-year-old boys as adults in the death of 39-year-old Dionecia Valencia, whose body was found after a house fire in the Big Hill area.

Valencia was stabbed and chopped to death in an ambush-style killing, the Tuolumne County Sheriff’s Office said in a news release Wednesday. Her body was found in a burned area near a dwelling that had been set on fire Aug. 13.

The boys were seen walking away from the fire as sheriff’s deputies and firefighters arrived just before 6 a.m.

Assistant District Attorney Eric Hovatter said a petition was filed last week for the juveniles to be prosecuted as adults.

“We alleged in the petition that they’re not suitable to be tried in juvenile court,” he said.

The office also filed a complaint charging both teens with first-degree murder, attempted murder, first-degree residential burglary, and arson of an inhabited structure.

Hovatter said the attempted murder and arson charges stem from a woman who was sleeping in the house when it was set on fire. He declined to release her name because he wasn’t sure if she requested to remain confidential. Deputies talked to the woman at the scene and is not a suspect, Hovatter said.

Before voters passed Proposition 57 in 2016, prosecutors could decide whether to try juveniles as adults. Now the county Probation Department completes a report for a judge to make the decision after hearing arguments from prosecutors and attorneys for the minors.

Hovatter said the suspects were in court on Friday but won’t enter pleas until the court determines whether to try them as adults.

Their next court hearing is scheduled for Sept. 6, though Hovatter said the court isn’t expected to make a determination on that date.

If the juveniles are tried as adults, their identities and court hearings will become public.

The teens, who Valencia knew, were arrested last week and are being held in custody, the Sheriff’s Office stated.

An autopsy conducted by the Stanislaus County Sheriff’s Coroner Office determined Valencia died of “multiple sharp force and chop force injuries” to her head and upper body.

Through physical evidence, statements and the autopsy, the Sheriff’s Office believes that Valencia was killed the night before the fire on Calle Quartz Road near Adelleana Lane.

Sheriff’s deputies and firefighters found a residence fully engulfed in flames.

Firefighters described the structure as a trailer of some sort, though the destruction was so severe it was hard for them to tell.

Deputies saw two male juveniles walking along the road while they were responding to the fire, but continued to the scene in case anyone needed to be rescued, the Sheriff’s Office said.

As firefighters worked to extinguish the burning structure, they learned of a second blaze in vegetation away from the home.

Blood, weapons and other evidence was found in that area and collected for further processing, the Sheriff’s Office stated.

The two juveniles were identified through a joint effort between sheriff’s detectives and the original responding deputies.

The suspects were later found, questioned and ultimately arrested based on several obtained statements and evidence, the Sheriff’s Office stated.

Sheriff’s Sgt. Andrea Benson said last week the boys were arrested after being transported by patrol deputies to the Sheriff’s Investigations Office and interviewed by detectives at about 5 p.m. the same day as the fire.

They were initially taken to the Mother Lode Regional Juvenile Detention Facility.

Hovatter said the suspects were being held on Wednesday at “various detention facilities,” though he declined to say which ones.

Presiding Judge Donald Segerstrom typically handles juvenile court and ordered the county Probation Department to generate a report, but Hovatter doesn’t know if he will make the decision on trying the boys as adults.

Hovatter said information about the case is still being gathered through an ongoing investigation.

Valencia’s Facebook page previously said she owned a cleaning business.

A GoFundMe was created on Aug. 14 by Valencia’s family and friends that stated she left behind five children.

“She touched so many of our lives; giving strength, love, loyalty, understanding and support when we needed,” the GoFundMe page stated.

The page had raised $1,720 from 34 people as of Wednesday. If funeral expenses are covered, proceeds will go to Valencia’s children.

Contact Alex MacLean at or (209) 588-4530.