Understanding Trends in Jail Populations, 2014-2019: A Multi-Site Analysis

This report examines and compares jail admissions, length of stay, average daily population, and bed days used in three U.S. counties from 2014 to 2019: Durham County, NC, Louisville-Jefferson County, KY, and St. Louis County, MO. This report summarizes three site-specific reports from Durham, Louisville and St. Louis. Together, these reports provide insights into changes in jail populations. This study was funded by the Pew Charitable Trusts and is part of a series of studies on jail populations in jurisdictions that make up The Research Network on Misdemeanor Justice (RNMJ), a project of the Data Collaborative for Justice (DCJ).

Key Findings:

  • Average LOS increased from 2014 to 2019 by 18% in Louisville, 24% in Durham, and 20% in St. Louis, which translates to individuals spending between 3.6 and 4.6 days longer in jail in 2019 compared to 2014. The increase in the average length of time that people stay in jail appears to be driven primarily by three factors:
    • Bail continues to be a key driver of jail populations. Average length of stay (LOS) for individuals with bail set above $5,000 increased between 31% to 54% in all counties
    • Younger people (ages 18-24) are staying in jails longer. In all counties, average LOS for adults increased to the greatest extent for the youngest group.
    • People admitted to jails on more serious charges are staying longer. In two of three counties, the average LOS for violent felonies increased by 23 or more days. In all counties, individuals admitted for a violent felony spent on average over 100 days in jail in 2019.
  • Black individuals were consistently overrepresented in the number of admissions and percent of occupied bed days.
    • In 2019, Black individuals made up 37% of the general population in Durham but 69% of admissions and 78% of bed days. In St. Louis, Black individuals comprised 25% of the general population but 55% of admissions and 67% of bed days, while in Louisville, 24% of the general population were Black individuals, who made up 39% of admissions and 49% of bed days.
    • In all counties, Black individuals stayed between 3.3 and 12.1 days longer in jail on average than white individuals.
    • From 2014-2019, Black individuals also saw larger increases in average LOS than white individuals in Louisville (21%) and St. Louis (34%).
  • Jail admissions in all three counties decreased by about a quarter from 2014-2019: 22% in Louisville, 25% in Durham, and 28% in St. Louis.
    • In all three counties admissions fell for property, drug, traffic, person, and society charges, with admissions cut in half for drug charges in Durham and traffic offenses in Louisville.
    • While admissions for felony charges fell in all three counties, misdemeanors and violations saw the largest declines, while admissions on warrants rose in all three counties.