What Is Probable Cause?
Probable cause must be based on factual evidence and not just on suspicion.
Most probable cause sources can be placed into four categories. These categories are:
- Observation – This is information that the officer obtains through their senses, such as sight, smell or hearing. This category is also used when an officer detects a familiar pattern of criminal activity that contains suspicious behaviors (i.e., flashing headlights, circling around a certain neighborhood.)
- Expertise – These are skills that officers are specially trained in, such as: being able to read gang graffiti and tattoos, detecting tools that are used in burglaries or knowing when certain movements or gestures indicate that a criminal activity is about to occur.
- Information – Statements provided by witnesses and victims, information provided by informants, and announcements made through police bulletins and broadcasts.
- Circumstantial Evidence – This is indirect evidence that implies that a crime has occurred but does not directly prove it.
For a judge to issue a search warrant, probable cause must show that it is likely that a crime took place and the person who is accused was involved in the criminal activity. If a search or arrest is made without a warrant, it must meet the standard of probable cause to be admissible in court.
Evidence obtained through searches and seizures made without probable cause can not be used against a defendant in court.