State Laws Affect Who’s in Jail, for How Long, and Why

Editor’s note: This page was updated Feb. 7, 2024, with word changes to improve clarity.

From 2010 to 2017, jail admissions fell 18%, while crime and arrests also fell, 14% and 20%, respectively. Yet the number of people held in county and municipal jails barely budged, hovering around 750,000 throughout this seven-year period and costing taxpayers $25 billion annually. With the American public in support of limiting the use of jail, the time was right for reform.

Jails are typically funded and managed at the county level. However, state policies regarding arrest, bail, sentencing, probation and parole, and court procedure can influence jail populations. State policymakers from all branches of government have a critical role to play when it comes to overseeing jail policy and populations.

In partnership with state officials, researchers, and community advocates, The Pew Charitable Trusts worked to advance consensus-driven state policies that safely reduced jail populations, expanded strategies to ensure that defendants appear in court, reduced people’s likelihood of re-arrest while awaiting trial, supported crime victims, and better aligned jail practices with research and constitutional principles. In 2019 Pew established a landmark partnership with a bipartisan group of policymakers in Michigan, where a historic slate of 20 jail reform bills were signed into law in 2021. The new laws restored driver’s licenses to 150,000 people, resulted in shorter probation terms, and reduced judges’ reliance on jail sentences for low-level offenses.

One pressing concern for Michigan leaders: Arrests for driving without a valid license were the third-most common reason for jail admission, and the state had suspended more than 350,000 licenses for failure to appear in court or pay fees. Pew found similar dynamics in North Carolina, where failure to appear in court was the most common reason for jail booking, and most missed court appearances were linked to minor driving offenses. Pew is now working with courts throughout the country to adopt policies that increase appearance rates, streamline case processing and resolution, and reduce the issuance of warrants, license suspension, and other collateral sanctions.

Pew’s research and counsel helped policymakers and other stakeholders better understand the dynamics of jail populations and enact reforms that protect public safety, ensure accountability, and reduce the number of people held in jails.