Bicycle Injury Lawyer, Criminal Defense Lawyer

Do the Police Need a Warrant?


Wisconsin and all states must abide by the 4th amendment concerning searches and search warrants. Although the 4th amendment and other laws are supposed to prevent searches by the police or government without a warrant, there are numerous exceptions.

Some common exceptions allowing police to search you or your property without a warrant include:

■A search performed after you are lawfully arrested-called a search incident to lawful arrest.

■A search of your vehicle based on probable cause.

■Evidence found in "plain view".

■A consent search. When you give the police permission to search you or your property.

■Stop and Frisk. The police can detain you and perform a pat of your outer clothes area without a warrant to protect themselves.

■Exigent Circumstances. Generally, your home has the most protection from unreasonable searches and only when there are "exigent circumstances" can the police enter your home without a warrant. Some of these would include if the police believe someone inside your home needs help, or if the police believe they need to enter to prevent the destruction of evidence.

■Community Caretaker. This exception is used by police when they need to check up on someone who they believe may be injured.


The 4th amendment as well as the Wisconsin Constitution prevent the government from conducting unreasonable searches. Search protections apply to people, cars, houses, any many other things/ areas. Wis. Const. Art. I, § 11 (2007) Section 11. Searches and seizures. The right of the people to be secure in their persons, houses, papers, and effects against unreasonable searches and seizures shall not be violated; and no warrant shall issue but upon probable cause, supported by oath or affirmation, and particularly describing the place to be searched and the persons or things to be seized.

Below are some common questions and hypothetical answers regarding search warrants in Wisconsin. (Note cases and notes are provided for general information and may be out of date and or overruled.  Every case has unique circumstances and therefore you should always investigate your personal case with a lawyer and not rely on any general hypothetical situations.) Also note that just because a search was valid in one case does not mean you should not argue against it in your case.  If you had a reasonable expectation of privacy and there was a warrantless search- challenge it.  Failing to do so will encourage the police and government to continue to search all of us without obtaining judicial approval first. 

1. Can a person use Electronic eavesdropping without your consent? Electronic Eavesdropping, done with the consent of one of the parties, does not violate the U.S. constitution.

 2. Can the police search you without arrest, probable, cause, or another exception if the police are only investigating a civil forfeiture and not a crime (like a 1st OWI)? The prohibition against unreasonable searches and seizures is not limited to criminal cases. It applies in forfeiture actions arising out of ordinance violations.

3. Can Police lock a car to protect its contents after arresting the driver. Probably. But if it is already locked, they cannot enter it and say they needed to just to lock the car.

4. Can police officers search a borrowed car if the lawful user of that car gives consent to search? Probably.

5. Is it legal for the police in to fly over houses at 800 feet and use standard binoculars and standard zoom camera lenses to surveil what is below? Courts have found this type of behavior legal.

6. If the police admit evidence that was seized in an illegal search at your trial, does it mean you get a new trial? Not necessarily, the court can find that other evidence that was uninfluenced by the inadmissible evidence was sufficient to convict you despite any illegal evidence.

7. Can the police look through your garbage without a search warrant? Probably, There is generally no reasonable expectation of privacy in garbage once it has been routinely collected by garbage collectors.

8. Can the police use evidence that they seized at your house in violation of your rights and based on a defective search warrant? Oftentimes under the inevitable discovery exception, the police might prove that they would have found the evidence anyway based on a later inventory or some other search.  Courts have also held that a sentencing judge can rely on evidence that was suppressed in imposing a sentence.  This is absurd-the evidence is inadmissible at trial but the sentencing judge can still consider it and hold it against the defendant.

9. If a police officer observes a traffic violation, stops your car to render assistance and inadvertently discovers criminal evidence in your car, can that evidence be used against you? Probably.

10. If you park your car at a hotel, can the police come by at night and use a police dog to sniff your car where it is parked without a warrant. Probably yes, courts have found there is no expectation of privacy around the air space around a car in a motel parking lot.

11. Can the police use infrared sensing devices to detect heat (example if someone is using grow lights) without a warrant? Most courts have found that using an infrared sensing device constitutes a search and requires a warrant.

12. Can a police officer search you or a bathroom stall you are in if you share the stall with another and leave the door slightly ajar. Probably yes because the there is evidence the stall is not being used for its intended purpose.

13. Do the police need a search warrant to search your porch or the inside of your house after viewing contraband through the porch? It depends, a court has found that a defendant had no reasonable expectation of privacy in a porch when the door to the living area was visible and an officer came to the defendant's residence for a legitimate purpose, and observed contraband from the porch through a window in the interior door.