PHOENIX — Editor's Note: The above video is from an earlier broadcast.
A Valley mother was sentenced Friday for killing her two young daughters last year by giving them prescription drugs.
Retta Cruse, 36, will spend the rest of her life in prison after pleading guilty to two counts of first-degree murder, according to the Maricopa County Attorney's Office.
Cruse was arrested last September after her two daughters, ages 4 and 9, were found deceased in the family's Phoenix apartment.
Police said Cruse used a mixture of prescription drugs and over-the-counter medication to sedate and overdose the girls before harming herself with a knife.
At the time of the incident, a witness told Phoenix police the mother had been upset over losing custody of one of her daughters, court records show.
Kevin Maddox, the father of one of the victims, told 12News last year he was given custody of his daughter and didn't understand why she was never returned to him in New Jersey.
“She took my baby's life from me," Maddox said. "From my family...from her sister.”
Maricopa County Attorney Rachel Mitchell said the young victims were "callously" killed by the one person who should have been protecting them from harm.
"This office is committed to ensuring justice for the most vulnerable in society and the killing of two young children at the hands of their mother is an unspeakable act,” Mitchell said in a statement.
Mitchell's office said Cruse will never be eligible for early release from prison.
Up to Speed
Catch up on the latest news and stories on our 12 News YouTube playlist here.
More ways to get 12News
On your phone: Download the 12News app for the latest local breaking news straight to your phone.
On your streaming device: Download 12News+ to your streaming device
The free 12News+ app from 12News lets users stream live events — including daily newscasts like "Today in AZ" and "12 News" and our daily lifestyle program, "Arizona Midday"—on Roku and Amazon Fire TV.
12News+ showcases live video throughout the day for breaking news, local news, weather and even an occasional moment of Zen showcasing breathtaking sights from across Arizona.