A Colorado woman accused of killing two of her young children during a custody dispute in December 2023 has been extradited from the United Kingdom to the U.S. to face murder charges, authorities announced Tuesday.

Kimberlee Singler, 37, was arrested in the U.K. on Dec. 30, 2023, after police say she drugged and killed her 9-year-old daughter and 7-year-old son, and injured her 11-year-old daughter before fleeing overseas, Colorado authorities said.

Colorado District Attorney Michael Allen confirmed during a news conference that Singler would make her first court appearance in the coming days on charges including two counts of first-degree murder, including two counts of first-degree murder, calling the development a “momentous day.”

Singler told police that a man who entered the apartment had committed the violent acts, and investigators initially treated Singler as a victim.

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Authorities said Singler’s daughter initially corroborated her version of events but later changed her story.

When police later attempted to arrest Singler, she was gone. Authorities eventually found her in an upscale London neighborhood.

Colorado Springs Police Chief Adrian Vasquez called the extradition a “significant milestone” in the case, noting that Singler is accused of committing an “unthinkable” act.

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“Crimes as horrific as this are simply heart-wrenching,” he said. “They’re just simply sad. No person, much less a child, should ever have to go through something like this.”

In their crime scene investigation in December 2023, Colorado authorities located spent rounds, a blood-stained knife and empty bottles of sleeping pills in a trash can.

Police found the two dead children in bed together.

At the time of the crime, Colorado Springs police said they received a 911 call reporting a burglary from Singler’s address, but investigators later said evidence did not support a burglary.

Both the Federal Bureau of Investigation and Colorado Springs police went to London to apprehend Singler, who fought extradition and has denied harming her children.

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In January 2025, a U.K. judge ruled that Singler could be extradited to the U.S. for trial, and her appeal was denied last month.

Her attorney argued against extradition, saying that Singler would be given a mandatory sentence of life without parole if convicted of first-degree murder in Colorado, which would violate a European human rights law.

The Associated Press contributed to this report.