The prison that the team goes to visit Speck at is actually the former West Virginia State penitentiary in Moundsville. It started life as a Civil War armory and afterwards was converted to a prison. You can still visit, at the east end of the complex, the hole that the prisoners would drop through as they were being executed. These were open to the public until well into the 1930's.
While Dr. Carr is attempting to classify different killers she mentions Charles Whitman and compares him to Richard Speck. Whitman was the infamous Texas Tower Sniper. He murdered his mother and wife before occupying the University Tower at UT at Austin, killing 17 people and wounding 31 others on August 1, 1966.