 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.Inmates who are considered to be politically threatening are sometimes put into isolation; although the United States does not officially hold political prisoners, some inmates in solitary confinement are there because of their political activism.This justification often means that minorities are more likely to end up in solitary confinement.