They call it “The Hole,” and the use of segregation units — where roughly 500 of the state’s 11,000 prisoners are held in Massachusetts on any given day — has come under increased scrutiny over the last year, as state and federal court rulings have limited the use of the units, and as state legislators have proposed regulating them further.
The Department of Correction defends what it calls special management units, saying they are needed to keep unruly inmates in order.
“We have to be realistic when we’re running these prisons . . . Segregation is a necessary tool in a prison environment,” said Luis S. Spencer, the department’s commissioner of correction. Full story for BostonGlobe.com subscribers.