TAMPA, Fla. (AP) - A University of South Florida researcher known for her work for the U.N. and for excavating graves at a shuttered boys school is now tackling some 50 cold cases.

Dr. Erin Kimmerle received a $385,000 grant from the National Institute of Justice for the cases.

Most are in Florida. Some are from Pennsylvania and Wisconsin.

Kimmerle uses state-of-the-art DNA testing and chemical isotope tests on the cases. Her lab is one of a handful nationwide to use this advanced study of minerals and geography to narrow down where a person is from through tooth, hair and nail analysis.

Kimmerle is a former United Nations International Criminal Tribunal investigator, a professor and a 44-year-old married mother of two. She investigated dozens of graves at Florida's Dozier School for Boys - where former students accused officials of abuse.