A new report from the Prison Policy Initiative shows that the populations of local jails are swelling for reasons that have little to do with crime.

State prison rates have come down modestly overall, reports the Sentencing Project, and some states can boast double-digit decreases since the turn of the century.

City and county jails, meanwhile, have been bloating. Roughly two-thirds of states have seen jail populations at least double since 1983 a dozen have seen jail populations triple.

Even many of those jailed for actual criminal convictions have likely landed there because of failures in the health care system or because other safety nets have given out. The report finds that 65 percent of those incarcerated in jails have diagnosable substance abuse disorders, while another 15.3 percent of those jailed report being homeless.

To read more of Brentin Mock's article, please click here.