The prevalence of sentenced prisoners among jail populations has decreased greatly since 1880. In 1880, 72% of the jail population consisted of sentenced prisoners. By 1970, that share was down to 43%. Recent jail statistics report the share of jail inmates (prisoners) who are convicted. Because conviction precedes sentencing, the share of convicted prisoners is larger than the share of sentenced prisoners. At mid-year 2009, the share of convicted prisoners among the U.S. jail population was 38%. The later figure does not include the large number of persons incarcerated at least overnight but less than for a few days. Hence the sentenced share of the jail population has decreased from 72% in 1880 to under 38% in 2009. The decline in the sentenced jail population suggests that less formal punishment has shifted from non-incarceration (probably corporal punishment) to incarceration.
The unsentenced jail population has shifted away from being much more male-biased than the sentenced jail population. In 1880, the ratio of males to females among the unsentenced jail population was 11.7, compared to a 4.5 male/female ratio among the sentenced jail population. In 2009, the sex ratios for unconvicted and convicted jail inmates were 7.4 and 6.9, respectively. Men are highly disproportionately represented among inmates in jails, as they are among inmates in prisons. However, relatively informal use of jail incarceration (incarceration without a sentence) has changed from being relatively rare and relatively highly male-biased to being common and no more male-biased than comparable sentenced imprisonment.
Legal Status of U.S. Jail Inmates
| year | unsentenced sex ratio | sentenced sex ratio | sentenced share |
|---|---|---|---|
| 1880 | 11.7 | 4.5 | 72.1% |
| 1890 | 13.4 | 5.3 | 70.3% |
| 1904 | 14.5 | 7.5 | 68.0% |
| 1910 | 15.0 | 6.1 | 67.0% |
| 1922 | 14.2 | 11.9 | 65.1% |
| 1933 | 14.2 | 14.4 | 59.2% |
| 1970 | 14.2 | 19.8 | 43.1% |
| 2009 | 7.4 | 6.9 | 37.8% |
| Note: 2009 figures are for unconvicted & convicted, rather than unsentenced & sentenced. Source: see US long-run prisoner statistics. | |||
The share of unsentenced prisoners in custody of the U.S. Federal Bureau of Prisons has fluctuated greatly from 1970 to 2004. Across this period the median share of unsentenced prisoners was 11%. However, in 1971 the unsentenced share was 1.7%, and in 1982 the unsentenced share was 25.6%. Relatively informal use of federal incarceration apparently has varied widely over roughly a decade.
Sentenced prisoners under state or federal jurisdiction account for a relatively stable share of all prisoners under state or federal jurisdiction. Since 1971, “sentenced prisoner” in statistics on federal and state prisoners has typically meant prisoners sentenced to a maximum sentence (i.e. not accounting for good-time or early-release mechanisms) of more than one year. Sentences of more than a year historically are associated with felons and with prisoners held in state prisoners, rather than in local jails. Recognized that a sentenced federal or state prisoner is defined as a prisoner sentenced to a maximum sentence of more than a year, the share of sentenced prisoners among prisoners under federal and state jurisdiction has median, minimum, and maximum yearly values of 4.2%, 3.6%, and 5.5%, respectively, from 1974 to 2010.
Sentenced prisoners under federal and state jurisdiction are the most prominent officially reported statistics on sentenced prisoners. Relatively informal use of incarceration (incarceration without sentence) isn’t visible in those statistics. Informal use of incarceration occurs primarily in local police lockups, local jails, and prisons under federal jurisdiction.