Every year millions of people cycle through America's prisons and jails. Many of them never make it home. Using information from a federal government database of more than 21,000 deaths, The Marshall Project is now able to show how people are dying in America's prisons and jails. For incarcerated people under the age of 55, just under half of the deaths we could identify were from largely preventable causes like suicide or drug overdoses. Older incarcerated people tended to die from natural causes. In more than a third of cases, we simply could not determine a cause of death, because there was not enough information. Our analysis is based on data collected by the Justice Department under the Death In Custody Reporting Act, which Congress passed a quarter-century ago with the intention of creating a record of everyone who dies in law enforcement custody. The data contained information like names, dates and brief descriptions of the circumstances surrounding each person who died in prisons, jails and during the course of arrest between Oct. 1, 2019 and Sept. 30, 2023. The government's data is riddled with errors. Not only did we find hundreds of deaths missing from the dataset, but the majority of the descriptions detailing how each person died didn't meet the government's own minimum quality standards. Almost one-in-10 of the deaths in the dataset were suicides " making it the third most common way people of all ages died.