Suicide by cop is a suicide method in which a person deliberately acts in a threatening way, with the goal of provoking a lethal response from a law enforcement officer, such as being shot to death.
While the phrase is colloquial (“cop” being slang for police officer) and primarily used in the United States media, it has become the most popular name for the phenomenon. Other names include death by cop, suicide-by-police, officer- (or police-) assisted suicide or the more technical Victim-Precipitated Homicide.
The idea of committing suicide in this manner is based on trained procedures of law enforcement officers with the use of deadly force. In jurisdictions where officials are so armed, there are usually set circumstances where they will predictably use deadly force against a threat to themselves or others. This form of suicide functions by exploiting this trained reaction. The most common is pointing a firearm at a police officer or an innocent person, which would reasonably provoke that officer or others to fire on them in defense. However, many variants exist, for example attacking with a knife or other hand-weapon, trying to run an officer or other person down with a car, or trying to trigger a presumed explosive device.
The factor that the entire phenomenon hinges on is the person’s state of mind, and their desire to end their own life. This can be difficult to determine after the fact if they have died. Some cases are obvious, such as pointing an unloaded or non-functioning gun (such as a toy gun or starter’s pistol) at officers, or the presence of a suicide note. Some suspects brazenly announce their intention to die before they act (e.g., the iconic declaration, “You’ll never take me alive!”). However, many cases can be more difficult to determine, as some suspects with the desire to die will actually use deadly force on and even kill people before being killed. Many law enforcement training programs have added sections to specifically address handling these situations if officers suspect that the subject is attempting to goad them into lethal force.
While only formally studied in late 20th century, the concept of deliberately precipitating one’s own slaying by the provocation of judicial officials may span back to the late Roman Empire. In 4th century northern Africa, a Donatist sect known as the Circumcellions (or “agonistici”) emerged that held the concept of martyrdom to be very sacred. On occasion, members of this group would assault Roman legionnaires or armed travelers with simple wooden clubs, in order to provoke them into attacking and martyring them. Others would interrupt courts of law, and verbally provoke the judge so that he would order their immediate execution (a normal punishment at the time for contempt of court). 
The first legal “Suicide by Cop” case in English legal history was a judgment made by Reverend Dr William Dolman while serving as a London coroner between 1993 and 2007. It set a legal precedent and the judgment, as a cause of death, has been a part of English law since.
The phenomenon has been described in news accounts from 1981, and scientific journals since 1985, although this particular phrase did not become common until the early 2000s. The phrase seems to have originated in the United States, but also appears in an article in the British newspaper The Guardian, dated May 10, 2003. The report states that a jury in a police-shooting inquest ruled it a suicide because on the scene, the subject reportedly stated “better get your guns out lads, I’m coming out” and a suicide note was later found. Some say that the 1976 death of Mal Evans, road manager, assistant, and a friend of the Beatles, was an example of this phenomenon. Some historians believe that Giuseppe Zangara, the man who killed Chicago mayor Anton Cermak in a possible attempt to assassinate then President-Elect Franklin D. Roosevelt, might have been attempting suicide by police.
Some of the first research into suicide by cop was completed by Sgt. Rick Parent of the Delta Police Department. Parent completed his doctoral thesis at Simon Fraser University, School of Criminology, Burnaby, British Columbia in 1996. It was titled “Aspects of Police Use of Deadly Force in North America: The Phenomenon of Victim-Precipitated Homicide.” Parent’s research of 843 police shootings determined that about 50% were victim precipitated homicide. Parent defined victim precipitated homicide as “an incident in which an individual bent on self-destruction, engages in life threatening and criminal behavior in order to force law enforcement officers to kill them