There is a persistent rumor that if you ask an undercover police officer or police informant if they're a cop, they are required to tell you. Based on this myth, many people believe they can safely conduct illegal transactions just by making sure to ask "Are you a cop?" first.

This idea is widespread and like many such myths, is most often transmitted by word of mouth. Examples can also easily be found on bulletin boards and newsgroups, in subculture publications, and in the media. The major variations of the myth include:

• Police have to identify themselves if specifically asked whether they are law enforcement.
  
  Example: "Are you scared that your friend or enemy is an undercover cop, just ask, they are required to tell you if they are reporting to law enforcement."¹
  
  
• Undercover officers aren't allowed to initiate a drug sale without pre-existing suspicion.²
  
  Example: "An undercover cop comes up to you and asks, 'Do you want to buy some drugs?' You say, 'Yes', and they arrest you. THAT is entrapment, and will be thrown out."³
  
  
• Undercover officers aren't allowed to ask for an illegal drug by name. Example: "He tells me that [undercover police] cannot ask you for drugs by name, or even common slang terms. They must call it something else, like 'fun stuff'."⁴

These types of myths are generally based on the belief that it is illegal for a police officer to entrap a citizen into committing a crime. Following this theory, many people believe that related actions by police, such as lying about their identity, would also be illegal or invalidate a prosecution. While a claim of "entrapment" by police can be used as a defense in a criminal case, it is both uncommon and rarely successful. Additionally, police entrapment itself is not illegal -- just potential cause for a not-guilty verdict.

Loosely defined, entrapment is a situation in which, if not for the actions of the police officer or police informant, the defendant would not have committed the crime. This defense is generally only successful in situations where law enforcement officers create a criminal plan, plant the idea of that plan into an otherwise innocent person's mind, and then instigate the plan for the purpose of prosecuting the suspect.

The mere presentation of an opportunity or request by an officer that an individual commit a crime does not qualify as entrapment. An officer may engage a citizen in conversation and ask to buy an illegal substance -- even if they have no reason to suspect the person of illegal activity.² They may offer to sell an illegal substance and arrest the buyer after the sale.

Factors Considered in an Entrapment Defense

The character of the defendant (whether the defendant was more "predisposed" to commit the crime than the ordinary citizen; e.g. having a record of illegal activity of this sort). Who first suggested the criminal activity. Whether the defendant engaged in the activity for profit. Whether the defendant demonstrated reluctance (and not just "no thanks, well ok": more like repeatedly refusing and then eventually, months or years later, giving in). The nature of the government's inducement (how much did they persuade, threaten, coerce, or harass).

They can go out of their way to help a person to commit a crime. What they can't do, is unduly persuade, threaten, coerce, or harass the person, such that a normally law-abiding citizen would participate in the unlawful action. Unfortunately, even in cases where the government does induce a crime, evidence that the defendant was "predisposed" to committing the crime is likely to undermine an entrapment defense. If the prosecution can show that the defendant agreed to participate too quickly or had a record of similar crimes in the past, the entrapment defense rarely succeeds.⁵ One example of such a case was U.S. v. Bogart (1986) in which Bogart agreed to sell presidential campaign posters to a police informant. When the informant arrived to purchase the posters, he informed Bogart that his only method of payment was with cocaine. Though Bogart initially refused, he eventually agreed because he needed the proceeds from the sale. He was arrested and his entrapment defense was denied based on his "predisposition" to commit the crime.⁶

The question of whether or not the police may lie during the course of their work goes hand in hand with the question of entrapment.

It is well accepted that deception is often "necessary" to catch those who break the law. There is no question that police officers are allowed to directly mislead and/or deceive others about their identity, their law enforcement status, their history, and just about anything else, without breaking the law or compromising their case.⁵ Conversely, it is illegal for an ordinary citizen to lie to the police in many jurisdictions.

Police officers working undercover have exceptions from certain criminal laws. For instance, law enforcement officers directly engaged in the enforcement of controlled substance laws are exempt from laws surrounding the purchase, possession, sales or use of illegal substances.⁷

This means that there's no way to identify an undercover officer based on their willingness or refusal to use an illegal drug. Reverse stings are common in the enforcement of controlled substance laws. In a reverse sting operation, a police officer sells drugs that have previously been confiscated and then arrest the buyer.

The myth that undercover police must admit to being police if asked has been around since at least the mid-1970s. In addition to the belief that entrapment is illegal, it may have roots in requirements that law enforcement identify themselves in some other situations.

1. Most on-duty police are required to wear both a uniform and a uniquely numbered badge identifying themselves as police.
2. Police must generally identify themselves before executing a search warrant or arresting someone.
3. Though it varies by jurisdiction, there are some situations in which off-duty police may be required to identify themselves, including if confronted by another police officer or before acting in their capacity as a police officer. The simple summary is that undercover police are given a great deal of latitude when investigating suspected criminals. They may lie, break controlled substance laws, ask to buy substances by name, offer drugs for sale and are not required to identify themselves during the course of their undercover investigations.