Also known as: probable-cause standard · probable cause · probable cause requirement
Written by attorneys · grounded in primary & secondary sources — see below
A legal standard requiring facts sufficient to warrant a prudent person in believing that a particular proposition is true.
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Federal agents submitted an affidavit detailing surveillance of a warehouse and statements from two employees that Parker Phillips stored stolen electronics inside. A magistrate reviewed the affidavit and found the facts sufficient to believe contraband would be found. The agents executed the warrant and seized the goods. Parker later moved to suppress, arguing the affidavit lacked the required showing.
Officers arrested Phoebe Park without a warrant after she was found with marked bills from a recent robbery. Within hours the prosecutor filed a complaint in the district of the offense that recited the officers' observations and the victim's identification. The magistrate reviewed the complaint and confirmed it met the required showing before the initial appearance. Phoebe's counsel moved for release, claiming the filing was untimely.
Philip Powell's will left his art collection to his niece and contained a clause forfeiting any gift to a beneficiary who contested the will. The niece filed a petition alleging undue influence by the executor. She presented medical records showing the testator's confusion and prior inconsistent statements. The court found the evidence supplied the required basis and refused to enforce the forfeiture clause.
An anonymous caller told police that Paul Peterson was selling cocaine from his garage and supplied the garage address plus the license plate of a frequent customer. Officers verified the plate and observed short visits consistent with drug sales. A magistrate issued a warrant after applying the flexible assessment that weighs all circumstances. Peterson moved to suppress, arguing the tip alone was insufficient.
Perry Pratt's will left his business to a longtime employee and included a clause penalizing any contest. His daughter filed a petition alleging lack of capacity, supported by hospital records from the week of execution and statements from caregivers. The probate court determined the records and statements supplied the required basis and held the clause unenforceable. The employee appealed, claiming the evidence was too speculative.
A prosecutor received a police report describing a bar fight but no witness could identify the aggressor. The prosecutor declined to file charges, concluding the evidence did not meet the required showing that the defendant committed the offense. The victim demanded prosecution and threatened a civil suit. The prosecutor explained that ethical rules barred proceeding without the necessary factual foundation.
Probable cause requires facts that would lead a prudent person to believe a crime has been committed or that evidence will be found. Reasonable suspicion is a lower threshold that justifies only a brief stop or frisk. Courts apply the higher standard to arrests and warrants because those actions involve greater intrusions on liberty.
Supporting sources
An informant's tip is evaluated under the totality of the circumstances. Veracity, reliability, and basis of knowledge are relevant but not rigid requirements. Strong corroboration of predictive details can compensate for weaknesses in any single factor.
…of police officers in investigating crime. See Escobedo v. Illinois , 378 U. S. 478, 492. When an individual is in custody on probable cause, the police may, of course, seek out evidence in the field to be used at trial against him. Such investigation may include inquiry of persons not under restraint. General on-the-scene…
…by. (Imagine the circumstances that would enable a search warrant to be obtained for a residence on the ground that there was probable cause to believe that consensual sodomy was then and there occurring.) Surely that lack of evidence would not sustain the proposition that consensual sodomy on private premises with the doors…
…is not invalid, then the police can invade the home to enforce it, provided, of course, that they obtain a determination of probable cause from a neutral magistrate. One of the reasons for the Court's holding in Griswold v. Connecticut , 381 U. S. 479 (1965), was precisely the possibility, and repugnance, of permitting…
…themselves and not by a judicial officer. They were not required, before commencing the search, to present their estimate of probable cause for detached scrutiny by a neutral magistrate. They were not compelled during the conduct of the search to observe precise limits established in advance by a specific court order. Nor were…
…a police officer from using deadly force to prevent the escape of a suspect who has committed a felony unless the officer has probable cause to believe that the suspect poses a significant threat of death or serious physical injury to the officer or others. I respectfully dissent. The public interest in the prevention of crime…
Supporting sources
A no-contest clause is unenforceable if the contestant had probable cause to institute the proceeding. Probable cause exists when the facts known at filing would lead a reasonable person to believe the will might be invalid. Courts examine medical records, prior drafts, and witness statements to decide whether that threshold was met.
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A magistrate's finding at a preliminary hearing that probable cause exists requires the defendant to appear for further proceedings. The finding does not preclude the government from later dismissing the case or the defendant from challenging the evidence at trial. A discharge for lack of probable cause does not bar a subsequent prosecution.
Supporting sources
Ethical rules prohibit a prosecutor from instituting or continuing a charge known to lack probable cause. The rule protects defendants from baseless prosecutions and preserves public confidence in the justice system. A prosecutor who files without the required showing risks professional discipline.
Supporting sources