Some 740,700 inmates were held in county and city jails in 2016, a recently released report from the Bureau of Justice Statistics shows, a slight increase from the number similarly incarcerated in 2015, but a notable decline from the 2008 peak of 785,500, a 30 year high.
There were 217 individuals held in jail per 100,000 population at the end of 2016, the report found, also a slight increase from the 215 per 100,000 in 2015. But that number was a definite decrease from the rate high of 259 per 100,000 at midyear 2007, further suggesting that jail populations are overall shrinking.
Jails are generally used for short-term purposes, such as holding those facing charges or awaiting sentencing, but not for extended-term punishments, for which prisons are usually reserved. As such, year-end counts of confined inmates—what is usually referred to as a jail's "stock"—may not adequately capture the fast turn-over time of prisoners passing in and out, what is generally distinguished as a "flow."
Because of this, the BJS provides two additional measures of jail size: Average daily population (ADP), which averages the total number of inmates in jail in a year over the number of days in the year; and annual admissions, which is the total number of people booked into the jail proper.
For 2016, the ADP continued the pattern of increasing slightly, to 731,300, but being down overall as compared against recent highs: ADP peaked in 2008 at 776,600 prisoners. Annual admissions declined slightly to 10,600,000 in 2016, itself a markedly lower figure than the 2008 peak of 13,600,000.
This is all good news for prison overcrowding: 80 percent of jail beds were occupied in 2016, down from 95 percent in 2007. That continues a general trend of decline, as jail capacity has increased and ADP has leveled off, the report showed. At the same time, there is still reason for concern: 17 percent of jails were at or above 100 percent of capacity in 2016.
As jail capacity has increased, another number has fallen: The number of juveniles incarcerated. Just one half of one percent of those in jails in 2016 were age 17 or younger; four out of five of those juveniles were awaiting trial for crimes for which they would be charged as adults. Juvenile incarceration hit a high of 1.2 percent of the overall jail population in 2000; the number has been steadily dropping since then.
Also of note in the report is the high proportion of individuals in jails who have not, in fact, been convicted. Among those incarcerated in 2016, an estimated 65 percent were "awaiting court action on a current charge," i.e., they had been arrested and were being detained in a jail because they were unable to pay bail, or otherwise were unable to be released. The remaining 35 percent were either offenders who had been sentenced or those offenders who had been convicted but were awaiting sentencing. Seventy-five percent of jailed inmates were facing felony charges.
The proportion of the jail population that is not yet convicted is a new high, a number that has been steadily growing since at least 2010. It is unclear as to whether or not this increase in proportion is due to more people being held prior to conviction, or fewer people being held after conviction.
Pre-trial detention in city or county jails has been a subject of some controversy among criminal justice reform advocates and civil libertarians, who argue that current practices—namely the institution of cash bail—keep many incarcerees in jails without conviction simply because they cannot afford to pay to bail themselves out.
In response to this criticism, a number of states have implemented alternatives to cash bail for certain offenses, while New Jersey has eliminated cash bail altogether. The BJS did not provide information on jail populations at a state-by-state level.