What is an Arrest?

An arrest is when a police officer has seized someone and placed them into custody. This does not necessarily mean the person was taken to the police station and booked. Many legal rights come into effect when someone is placed under arrest, making it a very crucial phase of the case. Many cases can turn on whether or not someone was placed under “arrest.”

Was the arrest “valid”?

In order for an arrest to be valid under the U.S. Constitution, it must be based on probable cause that the person had committed a crime. In many situations a warrant is required, but there are many exceptions to the warrant requirement. The determination of whether probable cause exists is made by police officers at the scene, but this conclusion can be challenged in court.

Probable cause is a tough word to define succinctly. Every case is different, and the facts of each case will determine what probable cause is. But a basic definition is:

1. when facts and circumstances exist within the arresting officer’s personal knowledge or (2) the police officer has reasonably trustworthy information to believe that an offense has been or is being committed

The determination of whether probable cause exists is based on the “totality of the circumstances” or all the facts surrounding the arrest. These can include, but are not limited to, the defendant’s statements, defendant’s behavior, and general observations of the arresting officer. In arrests that happen after a traffic stop, the officer can take such things into consideration as the driver’s behavior and how that person performs on field sobriety tests.

Being near criminal activity alone is not enough for probable cause to be established. The police officer must link the particular person to that criminal activity in some way.

What happens when the arrest is not “valid”?

Any arrest that is not based on probable cause is considered invalid and unconstitutional. Any evidence that is derived from an illegal arrest is excluded from being presented against the defendant in court. This is known as the exclusionary rule and its purpose is to make sure the Constitution is followed by arresting officers.