U.S. criminal procedure is codified in Title 18 of the United States Code. Sources include:

Criminal trials at the federal level are governed by the Federal Rules of Criminal Procedure. The Federal Rules of Criminal Procedure are incorporated into the U.S. Code either under Title 18 or in a separate Rules volume (see above for finding the U.S. Code). Alternative sources include:

Federal regulations pertaining to criminal procedure are generally located in Title 28: Judicial Administration. Check the index to the Code of Federal Regulations for other sections that may pertain to your topic. Sources include:

To locate state statutory code sections on your topic, consult the index to your state’s annotated code and look for relevant terms such as criminal procedure, arrest, law enforcement, jail, etc. The state statutory codes are located on the 3rd Floor of the Law Library.

There are also some compendia of state criminal procedure laws that may be useful for your research:

Most states have rules of criminal procedure, often modeled off the Federal Rules of Criminal Procedure. The Rules can often be found with the state's code, sometimes in a separate Rules volume (see state code resources above). Rules can also often be found on the state court's website. Sources include:

To locate state regulations on your topic, consult the index or table of contents for your state’s administrative code and look for criminal procedure, department of justice, attorney general or other related terms. The state administrative codes are typically located on the 3rd Floor of the Law Library.