Understanding Trends in the Jail Population in Louisville Metro, Kentucky: 2010 to 2019

This report and related research brief provide key metrics on the jail population in the Louisville Metro Detention Center (LMDC), including trends in jail admissions, length of stay, bed days utilized, and individuals who return to jail repeatedly. These reports provide key insights into the factors driving jail populations in LMDC and highlights key policy changes that may be influencing the number of people admitted to jail and how long they stay in jail. This study was funded by the Pew Charitable Trusts and is the first in 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:

  • Fewer low-level arrests have resulted in fewer jail admissions. Driven by fewer arrests for misdemeanors and violations, admissions to the LMDC declined by 35% between 2010 to 2019 – from a high of 43,724 admissions to 28,255 admissions. 
  • Increases in length of stay are a key driver of jail populations. Between 2010 and 2019, the average length of stay increased from 18.9 days to 30.4 days – a 60% increase that had a significant impact on the size of the jail population. The people who were most likely to stay in jail for more than 30 days were those who were booked on new charges, those awaiting transfer to state prison, and people charged with crimes against persons. 
  • Bail continues to be a key driver of the jail population. Length of stay decreased for those with bail set below $5,000; however, those with the higher bails saw a substantial increase in length of stay from 56 to 92 days and accounted for 86% of people with bail set who spent 180+ days in jail.
  • Black people are disproportionately represented in jail admissions and experienced significant increases in lengths of stay between 2010 and 2019. In 2019, Black people accounted for 39% of jail admissions but just over 20% of the population of Jefferson County. The average length of stay for Black people increased 15 days over the study period, compared to a 10 day increase for white people.
  • A significant proportion of people return to jail repeatedly. Of people jailed in 2010, 69.8% returned to jail at least once between 2010 and 2019 and over a quarter (27.7%) returned five or more times.