Legal Definitions - attenuation doctrine

The attenuation doctrine is a principle in criminal procedure that allows certain evidence to be used in court, even if it was initially discovered through illegal police conduct. This doctrine acts as an exception to the general rule that evidence obtained illegally, often referred to as "fruit of the poisonous tree," must be excluded.

Under the attenuation doctrine, if the connection between the illegal police action and the discovery of the evidence becomes sufficiently weak, remote, or "attenuated," the evidence may still be admissible. This means that intervening events, the passage of time, or the defendant's own voluntary actions can sometimes break the direct causal link between the initial illegality and the evidence, making it permissible for use in a trial.

Here are a few examples to illustrate how the attenuation doctrine might apply:

• Example 1: Voluntary Confession After an Illegal Stop

  Imagine police officers stop a person on the street without a valid reason, which is an illegal detention. During this illegal stop, the officers realize they know the individual from a previous interaction and recall there was a warrant out for their arrest on an unrelated charge. They then properly inform the person of their Miranda rights. After being read their rights and given time to consider, the person voluntarily confesses to a different crime entirely, one that was not the subject of the initial illegal stop or the warrant. In this scenario, a court might find that the voluntary confession, made after proper Miranda warnings and concerning an unrelated matter, was sufficiently "attenuated" from the initial illegal stop. The confession might be admissible because the direct link between the illegal stop and the confession was broken by the intervening lawful actions (Miranda warnings) and the defendant's voluntary choice.

• Example 2: Discovery of an Independent Arrest Warrant

  Suppose police officers illegally pull over a car without probable cause. While the driver is illegally detained, a routine check of their license plate and driver's information reveals there is an active, valid arrest warrant for the driver for a serious felony committed in another state. The officers then lawfully arrest the driver based on this warrant. During a search conducted incident to this lawful arrest, they discover illegal drugs in the car. Even though the initial traffic stop was illegal, the discovery of the pre-existing, valid arrest warrant is an intervening circumstance that breaks the causal chain. The evidence (illegal drugs) was found during a search incident to a lawful arrest based on the warrant, not directly as a result of the illegal traffic stop. Therefore, the connection between the initial illegality and the evidence is attenuated, and the drugs might be admissible.