To make a valid arrest or get an arrest warrant from a judge, the police must have probable cause. This is a different standard from the reasonable suspicion standard required to make an initial stop. Determining how much evidence is necessary to justify a finding of probable cause depends on the specific facts of the situation. A police officer needs more evidence than the level required for the reasonable suspicion standard, but they do not need to have enough evidence to prove that the suspect is guilty beyond a reasonable doubt. No percentage has been assigned to probable cause. Some judges seem to believe that the standard is less demanding than the preponderance of the evidence standard used in civil cases. Since that standard involves a greater than 50 percent probability, probable cause may not be what most people would consider “probable.”
Probable cause requires objective facts, not subjective beliefs.
A police officer must have more than a subjective hunch to make an arrest or get an arrest warrant. They need to have objective evidence that indicates the suspect’s responsibility for the crime. Even if a police officer believes that they have probable cause, a judge may not necessarily agree. They will review the information in the affidavit for the warrant and make a final decision. You should be aware that being guilty of a crime and having probable cause for an arrest are two different things. Probable cause may exist even if the defendant is not guilty.
This term can refer to either of two types of hearings. Generally, a probable cause hearing happens together with the defendant’s first court appearance after their arrest. The judge will determine whether probable cause supported the arrest. If it did not, law enforcement will not be able to continue holding the defendant in custody if they have not been released on bail or on their own recognizance. The other type of probable cause hearing happens after the prosecution has filed charges and involves the judge considering testimony on whether the defendant more likely than not committed the crime. If probable cause exists, the case will move forward toward trial.
If the police get a warrant before making an arrest, the warrant will satisfy the Fourth Amendment requirement of probable cause. However, since officers generally do not get a warrant before making an arrest, a judge often will need to determine whether probable cause exists soon after a suspect is taken into custody. The judge may make a finding of probable cause if they are persuaded by a written statement from the police or prosecution regarding the facts of the case.
Consequences of Arrest Without Probable CausePrompt action can be important for probable cause hearings. States may require a hearing within 24 hours after an arrest, but the U.S. Supreme Court has ruled that 48 hours is close enough for constitutional purposes. Even if the hearing occurs within the required period, a constitutional violation still may arise if law enforcement delayed the hearing for improper reasons, such as looking for evidence to support probable cause. Failing to meet the deadline likely will justify the suspect’s release unless law enforcement can show that there is an extraordinary reason warranting an exception.
Last reviewed October 2023
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