At any one moment, there are close to half a million people in jails across the U.S. who are locked up simply because their cases haven’t gone through the system, and they are too poor to post bail. Despite retaining the presumption of innocence, they are behind bars.

A Federal Reserve study found that a majority of Americans would not be able to come up with $400 in an emergency situation. As long as the current cash-bail system remains the primary arbiter of who is released before being put on trial, a majority of pretrial detainees will continue to be those who are poor. According to Cherise Fanno Burdeen, executive director of the Pretrial Justice Institute, only 10 percent of those held pretrial actually should be, because they pose a threat to public safety or are a flight risk.

Ironically, it is incredibly expensive to detain so many people pretrial. States and local governments spend roughly $9 billion a year detaining the legally innocent…

For those who cannot afford bail and have to remain in custody prior to trial, their time behind bars can last for months, or in some cases years. The Criminal Law Reform Project at the American Civil Liberties Union reviewed state laws nationwide. Some states—like Vermont, Washington and Wyoming—mandate that charges be presented to a grand jury for indictment or acquittal within days. Others don’t have charging statutes with time limits. As a result, arrestees in 20 states, including Alabama, Massachusetts, and Ohio, could conceivably be held indefinitely while waiting to be formally charged. Depending on how local jurisdictions interpret the right-to-counsel, many poor inmates will also have limited access to legal representation while they wait.

RTFA for some great interactive maps that take you state-by-state.