Private investigator

A private investigator (often abbreviated to PI; also known as a private detective, an inquiry agent or informally a private eye) is a person who can be hired by individuals or groups to undertake investigatory law services. Private investigators often work for attorneys in civil and criminal cases.

In 1833, Eugène François Vidocq, a French soldier, criminal, and privateer, founded the first known private detective agency, "Le Bureau des Renseignements Universels pour le commerce et l'Industrie" ("The Office of Universal Information For Commerce and Industry") and hired ex-convicts. Much of what private investigators did in the early days was to act as the police in matters for which their clients felt the police were not equipped or willing to do. Official law enforcement tried many times to shut it down. In 1842, police arrested him in suspicion of unlawful imprisonment and taking money on false pretences after he had solved an embezzlement case. Vidocq later suspected that it had been a set-up. He was sentenced to five years and fined 3,000 francs, but the Court of Appeals released him. Vidocq is credited with having introduced record-keeping, criminology, and ballistics to criminal investigation. He made the first plaster casts of shoe impressions. He created indelible ink and unalterable bond paper with his printing company. His form of anthropometrics is still partially used by French police. He is also credited for philanthropic pursuits – he claimed he never informed on anyone who had stolen for real need.

In the United Kingdom, Charles Frederick Field set up an enquiry office upon his retirement from the Metropolitan Police in 1852. Field became a friend of Charles Dickens, and the latter wrote articles about him. In 1862, one of his employees, the Hungarian Ignatius Paul Pollaky, left him and set up a rival agency. Although little-remembered today, Pollaky's fame at the time was such that he was mentioned in various books of the 1870s and immortalized as "Paddington" Pollaky for his "keen penetration" in the 1881 comic opera, Patience.

In the United States, Allan Pinkerton established the Pinkerton National Detective Agency—a private detective agency—in 1850. Pinkerton became famous when he foiled a plot to assassinate then President-elect Abraham Lincoln in 1861. Pinkerton's agents performed services which ranged from undercover investigations and detection of crimes, to plant protection and armed security. At the height of its existence, the number of Pinkerton National Detective Agency active agents and reserves rivaled the number of active soldiers and reserves in the United States Army. Allan Pinkerton hired Kate Warne in 1856 as a private detective, making her the first female private detective in America.

A larger role for this new private investigative industry was to assist companies in labor disputes. Some early private investigators provided armed guards to act as a private militia. During the union unrest in the US in the late 19th century, industrialists would hire Pinkerton agents as undercover operatives to infiltrate and disrupt union activity or serve as armed guards for factories. In the aftermath of the Homestead Riot of 1892, several states passed so-called "anti-Pinkerton" laws restricting the importation of private security guards during union strikes. The federal Anti-Pinkerton Act of 1893 continues to prohibit an "individual employed by the Pinkerton Detective Agency, or similar organization" from being employed by "the Government of the United States or the government of the District of Columbia."

Pinkerton agents were also hired to track western outlaws Jesse James, the Reno brothers, and the Wild Bunch, including Butch Cassidy and the Sundance Kid.

Many private detectives/investigators with special academic and practical experience often work with defense attorneys on capital punishment and other criminal defense cases. Others are insurance investigators who investigate suspicious claims. Before the advent of no-fault divorce, many private investigators sought evidence of adultery or other conduct within marriage to establish grounds for a divorce. Despite the lack of legal necessity for such evidence in many jurisdictions today, collecting evidence of spouses' and partners' adultery or other "bad behaviour" remain one of their most profitable undertakings, as the stakes nowadays are child custody, alimony, or marital property.

Private investigators can also perform due diligence for an investor considering investing with an investment group, fund manager, or other high-risk business or investment venture. This could help the prospective investor avoid being the victim of fraud. A licensed and experienced investigator could reveal the investment is risky and/or the investor has a suspicious background. This is called investigative due diligence, and is becoming more prevalent in the 21st century with the public reports of large-scale Ponzi schemes and other fraudulent investment vehicles.