Crime Spider - Search engine that crawls the web for law enforcement and crime related sites.
Crimenet - Australian based service provides a database of convicted criminals, con artists, frauds, scams, paedophiles, sex offenders, stolen property, missing persons, and unsolved crime.
Smoking Gun - Large collection of public documents on crimes, celebrities, politicians, and the FBI.
Crime News 2000 - True crime web links including criminal investigations, news archives and resources.
True Crime and Justice - Provides a collection of resources and articles on unsolved cases, homicide, forensics, missing persons, victims, domestic violence, drug wars, various types of abuse, and criminal activity.
Court Tv's Crime Library - Features stories and news on serial killers, the mafia, assassins, and forensics.
TheCrimePortal.com - Web directory includes news, prevention, statistics, law, famous crimes, forensics, corrections, and victims' sites.
Centre for Crime and Justice Studies (CCJS) - Charity which aims to inform and educate about all aspects of crime and the criminal justice system. Houses a wealth of UK criminal justice links, events, and publications, including The British Journal of Criminology and CJM.
Cold Case Center - Focuses on and aids law enforcement in the solving of unsolved homicides. Lists organizations, references, and news.
Detective Talk - Features a message board where you can post messages to help find missing persons and solve crimes.
Criminal Information Agency - Provides reports concerning all aspects of crime and criminality in the UK.
Arrested.Com Crime Center - Find stories from the FBI, CSI, and detectives. Includes amber alerts and high profile court cases.
CrimeWeb - Free web based service which allows the public to access and respond to missing adults, children, major crime and community security alerts which are created and distributed via the site by public safety agencies across the nation.
About.com: Crime and Punishment - News, essays, and links, including arguments, statistics, and information about specific issues.