The following stats are care of the Bureau of Justice Statistics (BJS), part of the U.S. Department of Justice. First, data on time served in state prisons, based on prison release records for 2016 from 44 states:
The average time served by state prisoners released in 2016, from initial admission to initial release, was 2.6 years, and the median time served was 1.3 years.
Persons released from state prison in 2016 served an average of 46% of their maximum sentence length before their initial release.
Persons serving less than one year in state prison represented 40% of first releases in 2016.
On average, state prisoners serving time for property, drug, or public-order offenses served less than two years before initial release.
Most offenders (59%) released from state prison in 2016 after serving time for drug possession served less than one year before their initial release.
So, how are US prisoners doing upon release? Turns out, not so good. This from a BJS nine-year follow-up study of state prisoners:
The 401,288 state prisoners released in 2005 had an estimated 1,994,000 arrests during the 9-year period, an average of 5 arrests per released prisoner. Sixty percent of these arrests occurred during years 4 through 9.
An estimated 68% of released prisoners were arrested within 3 years, 79% within 6 years, and 83% within 9 years.
Almost half (47%) of prisoners who did not have an arrest within 3 years of release were arrested during years 4 through 9.
More than three-quarters (77%) of released drug offenders were arrested for a non-drug crime within 9 years.
Forty-four percent of released prisoners were arrested during the first year following release, while 24% were arrested during year-9.
Eighty-two percent of prisoners arrested during the 9-year period were arrested within the first 3 years.
Five percent of prisoners were arrested during the first year after release and not arrested again during the 9-year follow-up period.
During each year and cumulatively in the 9-year follow-up period, released property offenders were more likely to be arrested than released violent offenders.
At least the US crime rate is going down:
References:
5 facts about crime in the U.S. by John Gramlich/Pew Research Center. October 17, 2019. https://www.pewresearch.org/fact-tank/2019/10/17/facts-about-crime-in-the-u-s/
Time Served in State Prison, 2016 Danielle Kaeble/ Bureau of Justice Statistics. Bulletin NCJ 252205. November 2018 https://www.bjs.gov/content/pub/pdf/tssp16.pdf
Update on Prisoner Recidivism: A 9-Year Follow-up Period (2005-2014) by Mariel Alper, Matthew R. Durose and Joshua Markman Bureau of Justice Statistics Special Report NCJ 250975 May 2018 https://www.bjs.gov/content/pub/pdf/18upr9yfup0514.pdf