GOVT 4000 (Fall 2021): The Politics of Policing : U.S. Policing, Crime, Sentencing, Incarceration Statistics and Data

"As part of a new initiative, the Sunlight Foundation has begun amassing an inventory of public and privately-produced criminal justice data.
The spreadsheet on this page is a work in progress ..."

Describes itself as "... a weekly newsletter of useful/curious datasets," but it's so much more. Do a word search for police to find a variety of datasets on policing, police misconduct, BLM protests and more.

Corrections, Courts & Sentencing, Crime Type, Employment & Expenditure, Federal, Law Enforcement, and Victims. Tip: Select Data Tools & Analysis (top) to construct custom tables.

This dynamic data analysis tool allows you to generate trend tables and figures of arrest data since 1980, including national arrest estimates and agency-level (police precinct) counts by offense, age, sex, and race. The underlying data are from the FBI's Uniform Crime Reporting (UCR) Program. 1980 - 2014

The Office of Research and Data collects data from documents submitted by the courts in each case in which a defendant is sentenced. From that data, the Commission prepares and disseminates public reports on a wide variety of sentencing issues.

A portal to a variety of US criminal justice statistics and publications.

The Gun Violence Archive is an online archive of gun violence incidents collected from over 2,000 media, law enforcement, government and commercial sources daily in an effort to provide near-real time data about the results of gun violence. GVA in an independent data collection and research group with no affiliation with any advocacy organization.
Data back to 2014.
See also: Tool from The Guardian which maps 2015 data down to the tract level.

Jail admissions ~ Jail incarceration ~ Pretrial jail incarceration ~ Prison incarceration for counties and states.

Transactional Records Access Clearinghouse (TRAC), an organization associated with Syracuse University that gathers, performs research, and distributes data about the activities of the federal enforcement and regulatory agencies. U.S. Customs Service, Federal Bureau of Investigation (FBI), Dept. of Homeland Security (DHS), Internal Revenue Service (IRS), Drug Enforcement Agency (DEA), the Bureau of Alcohol, Tobacco and Firearms (ATF), and the Immigration and Nationalization Serivce (INS).

"Mass shootings, detailed. The Violence Project’s Mass Shooter Database contains extensive details about public mass shootings in the US and their perpetrators, weapons, and victims, with a goal of “finding pathways to prevention.” The database, funded by a National Institute of Justice grant, covers 170+ shootings between 1966 and early 2020. Examples of the variables include: the perpetrator’s employment status, known prejudices, and experience with mental illness; the victims’ relationship to the perpetrator and estimated years of life they lost; and the firearms’ make, model, and method of acquisition." [Description from Jeremy Singer-Vine's "Data is Plural" newsletter.