Investigators say pollen indicates that a young girl whose remains were found stuffed in a bag on a Boston Harbor beach this summer lived in the area.

The girl was named Baby Doe by investigators and is estimated to be 4 years old. Her body was found on the shore of Deer Island on June 25, but her identity is a mystery.

Police have been chasing down tips from around the world, but experts determined pollen on the girl's blanket and leggings and in her hair came from trees found in New England. The Boston Globe reports that soot mixed in with the pollen told investigators her surroundings were urban, likely Boston.

Police have released a composite image of the girl and posted it on 84 billboards around the state.