SAN FRANCISCO - A California woman pleaded guilty Wednesday to torturing and murdering two young children who had been left in her care and disposing of their bodies in a rented storage unit.

Tami Joy Huntsman, 42, entered the pleas to two counts each of murder and torture in a Monterey County courtroom under a deal with prosecutors.

In exchange, they will seek a sentence of life in prison without the possibility of parole instead of the death penalty.

Get Breaking News Delivered to Your Inbox

"She will die in prison," prosecutor Berkley Brannon said, noting that the agreement also will spare the sister of the victims from testifying at a trial.

Police in Plumas County found the battered sister, who was 9 at the time, shivering and starving in the backseat of an SUV in December 2015. She had broken bones and told investigators that Huntsman and her boyfriend, Gonzalo Curiel, had severely neglected and abused the siblings after they moved into the couple's Salinas apartment.

Tami Joy Huntsman Redding Police Department via CBS Sacramento

Huntsman had agreed to care for the three children after their mother was killed in a car accident and their father - a relative of Huntsman - was sent to prison.

The older sister said Huntsman and Curiel killed her younger siblings on Thanksgiving after the 9-year-old was caught stealing a bagel, court records show.

On Wednesday, Huntsman acknowledged in court that she and Curiel starved and beat the 6-year-old boy and 3-year-old girl before killing them.

Police found the bodies stuffed in a plastic bin in a Redding storage unit about 300 miles north of Salinas.

Curiel was 17 at the time and is not eligible for the death penalty. Prosecutors have charged him as an adult with two murder counts and two torture charges.

Curiel, now 20, has pleaded not guilty. His trial is scheduled for April 2.