Two young children whose bodies were recently found in a Northern California storage locker were killed around Thanksgiving more than 300 miles away, authorities said.

Autopsies were performed on the bodies of the 3-year-old girl and 6-year-old boy Wednesday. Their names and the exact cause of death were not released.

Shasta County District Attorney Stephen Carlton told the Redding Record Searchlight that evidence found during the autopsy showed "clearly" the children were killed in Monterey County. The homicide investigation will now be transferred there.

A 39-year-old woman and her 17-year-old companion are under investigation in the deaths.

Carlton said the autopsy findings show that the children died around Thanksgiving while the family was still living in Salinas.

The case began on Friday, when a 9-year-old girl suffering from neglect and abuse was found near a house in Quincy, where the woman had recently moved.

Police then found the two children dead in a storage locker in Redding, which is about 150 miles away. The condition of the 9-year-old girl was not available Thursday.

The woman and the 17-year-old male were arrested and charged with child abuse, torture and mayhem. Each remained jailed on $1 million bail. They have been named as suspects in the two deaths, but they have not been charged.

Elliot Robinson, head of the Monterey County Department of Social Services, said the woman was visited by county child welfare workers four times over the course of a year to check on complaints of neglect.

None of the five children living in the apartment was removed from woman's care because there was no evidence they were at risk, Robinson said.

The complaints between September 2014 and August were about general neglect, a category that includes poor supervision, improper feeding, lice infestation and dirty household conditions, Robinson said, adding that none of the complaints alleged physical abuse.

"General neglect calls rarely will result in the removal of the child," he said.  "More often than not it's about poverty."

Two of the children at the home belonged to the woman, and the other three had been placed in her care by their incarcerated father after their mother died, Robinson said.

The Associated Press typically does not identify abuse victims; it is not naming the woman and a teenage suspect because their relationship to the children is unclear.

Plumas County Sheriff Greg Hagwood has said that some officials were so shaken by the abuse endured by the girl that they might have to take time off to recover.

The woman and teen appeared in court Tuesday, but they did not enter pleas. Their arraignments were set for Jan. 7. Their attorneys have declined to comment.

Social services officials were reviewing the agency's handling of the four neglect complaints.

Salinas police planned a news conference Thursday afternoon to discuss the case.