Antonio Hinojosa v. Connie Gipson

Prison gangs threaten the safety and security of prisons and prisoners. California has sought to combat these threats— and punish prison-gang affiliation — by segregating prison-gang members and associates from the general prison population. To that end, California houses prison-gang members and associates in Security Housing Units (SHUs), maximum-security facilities in which prisoners are kept in solitary confinement for over 22 hours a day.

California also encourages good behavior among its prisoners with good-conduct credits that reduce prisoners’ sentences. Most prisoners earn credits on a one-to-one basis — for one day of good conduct, they earn one day of credit. So, a prisoner who behaves well can potentially cut his sentence in half. But prisoners can also lose credits, or their credit-earning status can change, based on misconduct. Until 2010, prison-gang members and associates housed in SHUs earned credits at a 'reduced three-to-one rate. But California amended its penal code in 2010 to modify the credit-earning status of prison-gang members and associates in segregated housing. Those prisoners can no longer earn any credits, regardless their conduct. The…