A staff member in Paterno Library reported an unknown man exposed himself in the fourth-floor lobby of the library about 11 p.m. on Saturday, Penn State Police Services said.

The man is described as about 60 years old, 5 feet 9 inches tall and 180 pounds. He has gray hair and a mustache and was wearing brown shoes, a brown T-shirt and brown pants, police said.

The incident is still under investigation.