Child-killer Laurie Dann, who went on a shooting rampage in a suburban elementary school last month, was being treated with an experimental drug used to control a psychiatric disorder, it was reported Thursday.

Cook County Medical Examiner Robert J. Stein said an autopsy on Dann revealed traces of a drug called clomipramine, which is known by the trade name Anafrail.It is unclear why Dann, 30, who committed suicide after her May 20 shooting spree, was given the drug or where she received it, but her psychiatrist at the University of Wisconsin-Madison was authorized to dispense it as part of clinical tests being performed to meet federally mandated FDA requirements, The Chicago Tribune reported.