I've been there for about 7 investigations and I will say that the place is haunted but is over generally over dramatized on the internet. There are several "main" spirits there that seem to spend most of their time in certain areas of the prison but others do seem to roam freely in the cell blocks and other areas. I do know of one or two people that have felt that they have been pushed or hit. I have heard wisppers in my ears spotted movement etc mainly just regular haunting experiences. Nothing "evil" like a lot of people will claim. It is amazing however to experience the prison and go places that you normally would never be able to go. (unless you committed a crime

) My team and I have had spotty luck with gathering actual evidence there. Some of the problems with the location are,
1) A lot of people and in the large building sound carrys really well in certain areas. This causes problems when trying to record EVPs.
2) Some areas have a lot of things that will effect EMF meters. Pipes, wiring, metal walls, etc.
3) There are some areas where you can get a lot of dust orbs and false meter readings. One location of this is the place called "the sugar shack" this place is a common hot spot for ghost hunters but has a lot of rusting metal on the ceiling that comes down and gets in photos along with a fair amount of dust laying on the floor. The room is haunted but there are a lot of misinterpations from this room.
3) Moisture in some of the areas can be a problem.
4) Cracked windows and large stone rooms are responsible for some of the cold spots that people feel.
5) Pranksters, Although they don't show up for every public investigation of the place I have had encounters with people thinking its fun to jump out and scare people. There are also a lot of first time ghost hunters that commonly make mistakes and break the standards and protocols. I have no problem with new people taking up ghost hunting in fact I love it, but the ones that come for a one night experience commonly can effect an investigation in a negative way.
If you get a chance to go you should as it is great place to spend the night investigating the paranormal.
Jeremy Wiley
The United Paranormal Investigators Association