Intensive management unit refers to a prison within a prison for some of the state’s most violent and dangerous offenders. it is generally defined as holding someone in a cell, typically for 22 to 24 hours a day, with minimal human interaction.
IMU facilities are also used as housing for inmates who themselves are in danger.
Since Dan Pacholke – founder of the Sustainability in Prison Project and former Secretary for Washington State Department of Corrections implemented IMU facilities in prisons in the 1980’s, things have become quieter. Disturbances died down in the general population. Places became safer because those inmates who were most violent or disruptive could be isolated.
Restrictive housing has become a common tool for responding to all levels of rule violations, from minor to serious but being held in restrictive housing can result in significant negative effects. Solitary confinement can have lasting psychological effects on human beings and is now considered as cruel.
National and international organizations, including Human Rights Watch, have taken significant steps to reduce the use of restrictive housing.