Scottish immigrant Allan Pinkerton founded the world's largest private law enforcement agency, the Pinkerton National Detective Agency, in the 1850s, famous for infiltrating the Molly Maguires and pursuing outlaws like Jesse James and the Wild Bunch.
Allan Pinkerton (1819–1884)
August Vollmer, Berkeley's police chief in the early 1900s, was hailed as the "father of modern policing" for his innovative use of forensic science and technology, as well as his fight against police misconduct.
August Vollmer (1876–1955)
J. Edgar Hoover served as the first director of the FBI for nearly 48 years, known for apprehending notorious criminals but also criticized for surveillance of Martin Luther King Jr. and insufficient attention to white supremacist terrorism.
J. Edgar Hoover (1895–1972)
Sir Robert Peel, the two-time British Prime Minister, is considered the father of modern policing in the UK for founding the Metropolitan Police Service, which is responsible for law enforcement and crime prevention in Greater London.
Sir Robert Peel (1788–1850)
Kate Warne, the first female detective in the US and the only woman agent employed by Allan Pinkerton, is often overlooked despite playing a pivotal role in uncovering the 1861 Baltimore Plot to assassinate President-elect Abraham Lincoln.
Kate Warne (1833–1868)
Eliot Ness led The Untouchables in Chicago during Prohibition, bringing down notorious gangster Al Capone and inspiring depictions in various media, including the 1987 film with Kevin Costner.
Eliot Ness (1903–1957)
Frank Serpico is a famous New York police officer who exposed widespread corruption in the NYPD and was shot and wounded before he could speak out, later depicted in the movie 'Serpico' with Al Pacino.
Frank Serpico
Ellis Parker, dubbed "America's Sherlock Holmes," solved 288 of the 300 major crimes he worked on, but was later jailed for directing the kidnapping and torture of an attorney in the infamous Lindbergh baby kidnapping case.
Ellis Parker (1871–1940)
Detective Inspector Jack Slipper, nicknamed "Slipper of the Yard," led the investigation into the Great Train Robbery of 1963 and tracked down Ronnie Biggs in Brazil.
Jack Slipper (1924–2005)