A 22-year-old woman has pleaded no contest to kidnapping three young children of her half-sister who was killed last August, the Los Angeles County District Attorney's Office announced today.

Brittney Sue Humphrey entered an open plea yesterday to three counts of kidnapping. In an open plea, the defendant pleads to the court without negotiating a settlement with the District Attorney's Office.

She is scheduled to be sentenced on Sept. 7 and faces up to 26 years and four months in state prison.

Deputy District Attorney Tal Kahana with the Child Abduction Section is prosecuting the case.

Humphrey and her 27-year-old boyfriend, Joshua Robertson, allegedly kidnapped the three young children of Kimberly Harvill in August 2016. The three children were ages 5, 3 and 2 when the crime occurred.

The children were later found abandoned in New Mexico at a motel. Humphrey and Robertson were arrested later in Colorado.

Robertson and Alex Valdez, 29, have been charged with murdering Harvill, whose body was discovered in a remote area of Gorman on Aug. 14, 2016. They also face a special circumstance allegation of lying in wait, making them eligible for the death penalty.

A decision on whether to seek the death penalty will be made at a later date.

Robertson also was charged with one count of possession of a firearm by a felon and two counts of an unrelated arson and one count of possession of flammable material.

Robertson is scheduled to return Aug. 8 for a preliminary hearing. Valdez's preliminary hearing is ongoing.

Case BA449493 was investigated by the Los Angeles County Sheriff's Department.

Los Angeles County District Attorney / Case BA449493 / July 19, 2017