an offender who has committed a “serious disciplinary offense” may be put in solitary confinement as a punitive measure. inmates put into disciplinary segregation are not required to be given the same privileges as those put into administrative segregation, but the duration of their stay in isolation tends to be shorter. according to a magazine written by inmates in a california prison, the practice operates under a “guilty until proven innocent” protocol, holding prisoners in solitary confinement even before it is clear that they committed the infraction.