Special Agent Andrew Burke testified at Ariel Castro's sentencing Thursday.
Burke says bedroom windows were boarded shut from the inside with heavy closet doors. Burke says a door to one bedroom was modified with locks on the outside and the doorknob removed.
He says the house was divided in ways to make it more secure and to hide the existence of rooms.
Burke says a series of alarm clocks were wired to the front door, and some rooms had ventilation only to the attic because of the boarded-up windows. There also were chains in the women's rooms.
http://accesswdun.com/article/2013/8/264102