The following organizations provide in depth national data and research on a wide range of topics related to criminal justice. They also provide state by state breakouts on some issues.
The Sentencing Project
The Prison Policy Initiative
The Vera Institute of Justice
Brennan Center for Justice
Data on Iowa arrests and convictions, on a county by county basis, are collected by the Division of Criminal and Juvenile Justice Planning of the Iowa Department of Human Rights. These can be found at www.humanrights.iowa.gov. Data on prison admissions, releases and the current prison population can be found on the Iowa Department of Corrections website.