CHICAGO (CBS) — A woman was released without charges Thursday, after detectives questioned her about the homicide of a baby girl in the Lawndale neighborhood.

Police said a woman walked into the Ogden District station around 6 p.m. Wednesday, and told officers her child was dead.

Investigators went to her home near 19th and Harding, and found 15-month-old Nicole Davis unresponsive at the scene.

An autopsy on Thursday determined Nicole died of multiple injuries from an assault, and her death was ruled a homicide.

Police said the woman who had been questioned in the death was released without charges on Thursday, pending further investigation.

The Illinois Department of Children and Family Services confirmed it also was investigating Nicole’s death, following allegations of neglect and abuse.

The state’s child welfare agency had no previous cases involving Nicole, but had investigated her caregiver before, a spokesperson said. Before Nicole was born, her caregiver was the subject of six DCFS investigations, involving a child born in 1999, but all of the allegations were ruled unfounded. Details of those cases have been expunged, and were not available.