Basis in Fourth Amendment

• Probable cause is a concept derived from the Fourth Amendment to the U.S. Constitution, which prohibits unreasonable searches and seizures.
  
  

Function

• Before police may arrest a suspect, they must have probable cause to believe that he has committed a crime.
  
  

Considerations

• Probable cause does not require absolute certainty on the part of the police that a crime has been committed. The quantity of evidence needed to meet the constitutional probable cause standard is evidence from which a reasonable person may conclude that a suspect has committed or is in the process of committing a crime.
  
  

Supreme Court Interpretation

• The Supreme Court, in a 1983 case, clarified the appropriate standard for probable cause when it ruled that a "substantial chance" or "fair probability" that criminal activity has occurred is sufficient to constitute probable cause for an arrest.
  
  

Contents Of Memorandum

• The memorandum will contain a description of the particular circumstances surrounding the arrest, as well as the applicable case law, or precedent, to support an argument to a judge at a hearing that the arrest failed to pass constitutional muster under the constitutional probable cause standard.
  
  

Procedure

• The memorandum to dismiss for lack of probable cause is submitted to the court. Upon receipt, the clerk's office will then schedule the matter at a later date for a hearing before the judge.