Authorities have released notes written by the Ohio State University janitor who shot two supervisors before killing himself, and he appears to tell a woman named Donna "sorry I let you down."

Police say Nathaniel Brown shot two supervisors early Tuesday before killing himself. Records show he shared the same address with a woman named Donna Dunson, although their relationship is unclear. Messages left at the home Thursday seeking comment were not immediately returned.

The coroner's office in Columbus on Wednesday released the notes from Brown, but did not say where they were found.

One supervisor who was shot died at the scene. The other, Henry Butler, is home from the hospital. He has not commented publicly.

Ohio State President Gordon Gee says the university will learn from what happened.