A 4-year-old Philadelphia girl was physically abused and eventually murdered by a caretaker her mother trusted, according to the Philadelphia District Attorney’s office.

Samilya Brown. Philadelphia Police

Police responded to a call on Oct. 30, where Samilya Brown said Zya Singleton had injured herself by falling out of a second-floor window while playing with a cat, the DA's office said, but doctors found inconsistencies in Brown's story. The 4-year-old died on Nov. 3.

The medical examiner then found what the DA called "horrific" signs of abuse: cigarette burns, bite marks, malnourishment, and wounds apparently treated with homemade stitches that had become infected.

Investigators say the story of Zya falling from the window was invented, and the child's cause of death was the abuse and neglect inflicted by Brown.

Brown, 38, was charged Tuesday with murder and endangering the welfare of a child.

The DA's office says Zya's biological mother had given custody of the child to Brown to keep the girl out of foster care. The two women had known each other for years, but the mother apparently did not know of the abuse. The mother was able to see Zya before she died.

“This child was killed, and was killed brutally, and was abused for an extensive period of time,” Philadelphia DA Larry Krasner said at a press conference Tuesday, reports NBC Philadelphia. "This is a horrific, heartbreaking case of abuse, neglect and murder of an innocent, defenseless child."