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Constitional Issues

Arrests, Searches, And Probable Cause

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The following is not legal advice but is for information only. Legal advice is when an attorney applies the law to a person's individual circumstances and advises them on their legal options or potential exposure to legal harm, which a web page clearly does not.

Arrests and probable cause

All arrests require probable cause - a rather vague term that courts struggle to define. When probable cause is defined it is often against a defendant. Sometimes, however, it is so blatantly lacking that courts have no choice but to suppress the evidence.

Probable cause is a legal standard that refers to the level of proof required for a law enforcement officer to conduct a search, make an arrest, or obtain a warrant. It is somewhere between more than the basic facts needed to suspect someone sufficient to conduct a Terry stop, but less than 51% of proof that would win a civil case (known as preponderance of the evidence or 'more likely than not').

In practice, probable cause can be established through a variety of means, including eyewitness testimony, physical evidence, or a combination of both. Once probable cause has been established, a law enforcement officer may arrest an individual, conduct a search of their person or property, seize items, or obtain a warrant to conduct a more extensive search. Warrants are nearly always needed to arrest a person at home (unless there’s an emergency that means there isn’t enough time to get one) or to search it.

Probable cause is a constitutional requirement under the Fourth Amendment of the United States Constitution, which protects individuals from unreasonable searches and seizures. If a search or arrest is conducted without probable cause, any evidence obtained may be deemed inadmissible and be suppressed as a remedy for a violation.


Searches also need probable cause - a standard often said to be that a criminal offense is ‘probable’ based on facts as they are known at the time. By way of some examples, a person’s car could be searched with an admission that they just bought drugs or there’s an alert by a drug sniffing dog that drugs are in a car. Probable cause wouldn’t exist if a police officer just asks a person to get out of their car and start rummaging around inside it over a speeding ticket since there would be no evidence of speeding to find inside a vehicle.

Things like bags and containers that can be searched have to be able to contain what is being looked for. A person suspected of stealing a TV or a candy bar would not be hiding it in a wallet, for instance.

The United States Supreme Court has also said that cell phone searches require a warrant - and even then it is not a carte blanche to search the whole phone. A search for a photo would not mean searching text messages or emails - without some basis for it. Cell phones contain so much information about a person’s life that they are deemed worthy of special privacy protections by the Supreme Court. This area of law related to technology is still developing.

There are also circumstances where what would not appear to be a search will become one merely because of the intrusion. For instance, police can - just like a mailman or UPS driver - come to the door of your home and ring the doorbell. They do not have a license to look in your windows or wander around into the back yard. Any evidence gained by deviating from that norm could also be regarded as a search that requires a warrant and probable cause. Without it, evidence when found a a result is suppressed for violating the constitution (specifically the Fourth Amendment).

The kinds of circumstances and issues that involve searches are really too numerous to mention - but this at least gives a primer on what issues could he considered. These were but a few examples.  It is important that a defense lawyer be alert to the factual and legal issues of a particular case and to make an argument that evidence be excluded when state action becomes potentially unconstitutional - because sometimes winning a motion to suppress can end a case. Whenever news reports say a case was dismissed on a technicality, they are often referring to the United States Constitution - as if that document and reason for dismissal is merely something worthy of a hand wave. Your defense attorney should regard it as vital to the protection of your rights enshrined within it - and hold the government to account when those rights are ignored.

One final note on this subject. Maine has an equivalent to the Fourth Amendment in its own constitution - called Article 1 Section 5. However, it has become meaningless, while some states have given its citizens additional protections against unreasonable searches and seizures. Maine's highest court has instead opted to subcontract interpretation of Maine's constitution to federal courts - being a minority of a minority of states (six out of 13) to have never deviated from the Fourth Amendment and also be among the half dozen to say it will never do so.

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