An Aurora mom has been arrested several days after her 4-year-old son died.

The boy, who police have not identified, died late on May 16. Police responded at about 10 p.m. to the 14100 block of East Tennessee Avenue after a report was made about the young boy not breathing. Aurora Fire-Rescue paramedics attempted life-saving measures on the boy, who had significant injuries.

He was taken to a local hospital, where he later died from his injuries.

Police interviewed the boy’s caretaker, Alexander Martinez-Armstrong, 24, who allegedly admitted to striking the boy repeatedly before his death, police said. Martinez-Armstrong was arrested the same day and faces charges of first-degree murder, police said. He is not the boy’s father.

Police said the boy’s mother, Destini Rose Lipsky, 23, was arrested Thursday in Colorado Springs following additional investigation from police. She faces a charge of child abuse resulting in death.

Martinez-Armstrong remained in the Arapahoe County jail Saturday. He is being held without bond. Lipsky remained in jail in El Paso County Saturday morning on $500,000 bond. Police said she will be transferred to Arapahoe County.

The investigation into the incident remains active, police said. Anyone with information about Lipsky and her interactions with her son are asked to contact Metro Denver Crime Stoppers at 720-913-7867.