Yes. Police can act on anonymous tips if they follow the rules, laws, and procedures that have been developed in accordance with the U.S. Constitution.
Police contact with people usually occurs:
- on public streets,
- in motor vehicles,
- in homes or other buildings.
The Fourth Amendment of the United States Constitution guarantees:
The right of the people to be secure in their persons and houses against unreasonable searches and seizures, and no Warrants shall issue, but upon probable cause, particularly describing the place to be searched, and the persons or things to be seized.
A police officer may, in appropriate circumstances, approach you for purposes of investigating possibly criminal behavior.
An investigative detention without a warrant must be based on a reasonable suspicion that:
- Some activity out of the ordinary has taken place;
- The activity is related to crime; and
- You (the detainee) are involved in the activity.
The justification for the stop or detention by police must include:
- Specific and articulable facts which support the police intrusion,
- Based upon the totality of the circumstances.
If police are acting on an anonymous tip, courts will consider whether:
- Police have confirmed or verified the information,
- If the information is specific and/or reliable,
For example: Did the tip include the make, model, and license plate of your vehicle?
If police exceed their authority in stopping, detaining or arresting you, then:
- Evidence can be suppressed or thrown out, and
- Your criminal case could be dismissed.
Detentions Based on Anonymous Tips
A tip from an anonymous source may provide reasonable cause to detain you if it includes some facts that are verified by police. See Alabama v. White (1990) 496 U.S. 325.
A detention must be based on a reasonable suspicion that:
- some activity out of the ordinary has taken place;
- the activity was related to crime; and
- you were involved in the activity.
A search made during investigative detention is illegal if:
- there was no basis for an officer to believe you were armed and dangerous;
- the scope of the search was beyond a pat-down for weapons; or
- the search extended to your possessions or vehicle, except that an officer may order you to produce identification.
A real-life example is:
Two separate people approach police on a crowded New Year’s Eve street and tell them a man in a white cap has a gun. The police can see only one man in the crowd with a white cap. They approach the man, pat him down, and find a gun. The court ruled the encounter was justified. People v. Coulombe (2000) 86 Cal. App. 4th 52.
Vehicle Stops
Police must have probable cause or reasonable suspicion of criminal activity to stop your motor vehicle. Sometimes an anonymous tip can be sufficient.
The justification for the stop or detention by police must include:
- specific and articulable facts which support the intrusion,
- based upon the totality of the circumstances.
Courts will look at the source of the information that police are relying on:
- is it confirmed or verified by the police?
- is it reliable?
For example:
An anonymous 911 caller told police that a truck had run her off the road. The caller provided the vehicle description and license plate number. Officers quickly located and stopped the truck. The officers smelled marijuana, searched the vehicle and found 30 pounds of the drug. The court ruled that based upon the totality of the circumstances, the officers had reasonable suspicion to think the driver might be intoxicated and could stop the vehicle to confirm. See Navarette v. California (2014) 572 U.S. 393.
An investigative detention is illegal if it is based on only one insufficient factor, such as:
- curiosity, rumor, or a hunch;
- your race or sex;
- your presence in a high-crime area; or
- your nervous behavior.
Searching Residences
Police must obtain a warrant to search your house. An anonymous tip, standing alone, does not provide the necessary probable cause for the issuance of a warrant.
The affidavit for a search warrant must include:
- sufficient information to conclude that the informant is honest, and/or
- facts indicating that the information is reliable along with the basis of the informer’s knowledge.
The anonymous informant must actually witness the alleged criminal activity.
For example:
A tip by an anonymous informant that there was heavy foot traffic at a person’s residence, by itself, is not sufficient to establish probable cause. See Bailey v. Superior Court (1992) 11 Cal. App. 4th 1107.
Please note there are exceptions to the search warrant requirement for a house or vehicle:
- exigent circumstances,
- search incident to a lawful arrest,
- consent,
- plain view,
- caretaker function,
- motor vehicle exception,
- vehicle inventory.
Please note that in any criminal case involving anonymous tips, arrests, or searches, it is VITAL to consult with an experienced criminal defense attorney.
If police exceed their authority:
- evidence can be suppressed or thrown out, and
- your criminal case could be dismissed.
Additional reading
For more in-depth information, refer to these scholarly articles:
- Presumed Drunk until Proven Sober: The Dangers and Implications of Anonymous Tips Following Navarette v. California – South Dakota Law Review.
- J.L.’s Time Bomb Still Ticking: How Navarette’s Narrow Holding Failed to Address Important Issues Regarding Anonymous Tips – University of Baltimore Law Review.
- The Big Picture View of Anonymous Tips from Ordinary People – Touro Law Review.
- Requiring Independent Police Corroboration of Anonymous Tips Reporting Drunk Drivers: How Several State Courts Are Endangering the Safety of Motorists – University of Cincinnati Law Review.
- Anonymous Tips, Investigatory Stops and Inarticulate Hunches – Alabama v. White, 110 S. Ct. 2412 (1990) – Harvard Civil Rights-Civil Liberties Law Review.