Probable cause

From Wikipedia, the free encyclopedia
Jump to: navigation, search

In United States criminal law, probable cause is the standard by which an officer or agent of the law has the grounds to obtain a warrant for, or as an exception to the warrant requirements for, making an arrest or conducting a personal or property search, etc. when criminal charges are being considered. It is also used to refer to the standard to which a grand jury believes that a crime has been committed. This term comes from the Fourth Amendment of the United States Constitution:

The right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated, and no Warrants shall issue, but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

"Probable" in this case may relate to actual statistical probability, or to a general standard of common behavior and customs. The context of the word "probable" here is not exclusive to community standards and does not predate statistics, as some have suggested.[1]

Definition in the United States[edit]

A common definition is "a reasonable amount of suspicion, supported by circumstances sufficiently strong to justify a prudent and cautious person's belief that certain facts are probably true".[2] Notable in this definition is a lack of requirement for public position or public authority of the individual making the recognition, allowing for use of the term by citizens and/or the general public.

In the context of warrants, the Oxford Companion to American Law defines probable cause as "information sufficient to warrant a prudent person's belief that the wanted individual had committed a crime (for an arrest warrant) or that evidence of a crime or contraband would be found in a search (for a search warrant)". "Probable cause" is a stronger standard of evidence than a reasonable suspicion, but weaker than what is required to secure a criminal conviction. Even hearsay can supply probable cause if it is from a reliable source or supported by other evidence, according to the Aguilar–Spinelli test.

In the supreme court case Brinegar v. United States, the Supreme Court defines probable cause as “where the facts and circumstances within the officers' knowledge, and of which they have reasonably trustworthy information, are sufficient in themselves to warrant a belief by a man of reasonable caution that a crime is being committed.”[3]

Probationers and parolees[edit]

In early cases, the Supreme Court held that when a person is on probation, the standard required for a search to be lawful is lowered from "probable cause" to "reasonable grounds"[4] or "reasonable suspicion." Specifically, the degree of individualized suspicion required of a search was a determination of when there is a sufficiently high probability that criminal conduct is occurring to make the intrusion on the individual's privacy interest reasonable. The Supreme Court held, "Although the Fourth Amendment ordinarily requires the degree of probability embodied in the term 'probable cause,' a lesser degree satisfies the Constitution when the balance of governmental and private interests makes such a standard reasonable...When an officer has reasonable suspicion that a probationer subject to a search condition is engaged in criminal activity, there is enough likelihood that criminal conduct is occurring that an intrusion on the probationer's significantly diminished privacy interests is reasonable."[5]

Later, in Samson v. California, the Supreme Court ruled that reasonable suspicion is not even necessary: "The California Legislature has concluded that, given the number of inmates the State paroles and its high recidivism rate, a requirement that searches be based on individualized suspicion would undermine the State's ability to effectively supervise parolees and protect the public from criminal acts by reoffenders. This conclusion makes eminent sense. Imposing a reasonable suspicion requirement, as urged by petitioner, would give parolees greater opportunity to anticipate searches and conceal criminality."

The court held that reasonableness, not individualized suspicion, is the touchstone of the Fourth Amendment.[6] It has been proposed that Fourth Amendment rights be extended to probationers and parolees, but such proposals have not gained traction.[7] There is not much that remains of the Fourth Amendment rights of probationers after waiving their right to be free from unreasonable searches and seizures.[8] An essay called "They Released Me from My Cage...But They Still Keep Me Handcuffed" was written in response to the Samson decision.[9]

It has been argued that the requirement that a police officer must have individualized suspicion before searching a parolee's person and home was long considered a foundational element of the Court's analysis of Fourth Amendment questions and that abandoning it in the name of crime prevention represents an unprecedented blow to individual liberties.[10]

Use of trained drug dogs[edit]

Using a trained dog to smell for narcotics, has been ruled in several court cases as sufficient probable cause. A K-9 Sniff in a public area, is not a search according to the Supreme Court’s ruling in 1983 United States V Place. This particular case, Place was in the New York Airport and DEA agents took his luggage, even with his refusal to have the DEA search his bag. There was the smell of drugs from his luggage, and the trained dog alerted the agents. When the dog alerts their officers, this gives the probable cause for the luggage to obtain a warrant. The DEA then got a warrant and found a lot of drugs in Place’s luggage. It was not a search (until after the warrant) because a trained dog can sniff out the smell of narcotics, without having to open and look through the luggage.

The power of probable cause by K-9 units smelling for drugs is not limited to just airports, but even in public parking lots, high crime neighborhood streets, mail, visitors in prisons, traffic stops and schools, etc. If the incident where the dog alerts its officer and is dealing with one of the exceptions to a warrant, such as plain view, incident to arrest, automobile, exigency, or with a stop and frisk, the probable cause from the dog is enough to conduct a search. During a traffic stop and checkpoint it is legal for a police to allow a drug dog to sniff the exterior of the car. This is legal as long as it does not cause the traffic stop to be any longer than it would have been without the dog. If the dog finds a scent, it is again substitute for probable cause.[11]

Accident investigation[edit]

The term is used in accident investigation to describe the conclusions reached by the investigating body as to the factor or factors which caused the accident. This is primarily seen in reports on aircraft accidents, but the term is used for the conclusion of diverse types of transportation accidents investigated in the United States by the National Transportation Safety Board or its predecessor, the Civil Aeronautics Board.

Other countries[edit]

In the criminal code of some European countries, notably Sweden, probable cause is a higher level of suspicion than "justifiable grounds" in a two level system of formal suspicion. The latter refers only to the suspect being able to and sometimes having a motive to commit the crime and in some cases witness accounts, whereas probable cause generally requires a higher degree of physical evidence and allows for longer periods of detention before trial. See häktning.

Related cases[edit]

  • The Supreme Court decision Illinois v. Gates[12] lowered the threshold of probable cause by ruling that a "substantial chance" or "fair probability" of criminal activity could establish probable cause. A better-than-even chance is not required.
  • The decision in Terry v. Ohio,[13] established that "stop and frisks" (seizures) may be made under reasonable suspicion if the officer believes a crime has been committed, is, or soon will be committed with a weapon concealed on such person.
  • In United States v. Matlock,[14] the Court announced the "co-occupant consent rule" which permitted one resident to consent in the co-occupant's absence. The case established that an officer who made a search with a reasonable belief that the search was consented to by a resident did not have to provide a probable cause for the search.
However, in Georgia v. Randolph,[15] the Supreme Court ruled, thus replacing Matlock, when officers are presented with a situation wherein two parties, each having authority to grant consent to search premises they share, but one objects over the other's consent, the officers must adhere to the wishes of the non-consenting party.[16]
  • New Jersey v. T. L. O.,[17] set a special precedent for searches of students at school. The Court ruled that school officials act as state officers when conducting searches, and do not require probable cause to search students' belongings, only reasonable suspicion.
  • In O'Connor v. Ortega,[18] the Court relied on T.L.O. to extend the reasonable suspicion standard to administrative searches of public employees' belongings or workplaces when conducted by supervisors seeking evidence of violations of workplace rules rather than criminal offenses.

Probable cause hearings[edit]

In the various states of the United States, a probable cause hearing is the preliminary hearing typically taking place before arraignment and before a serious crime goes to trial. The judge is presented with the basis of the prosecution's case, and the defendant is afforded full right of cross-examination and the right to be represented by legal counsel. If the prosecution cannot make a case of probable cause, the court must dismiss the case against the accused.

See also[edit]


  1. ^ Hald, Anders (1990). A History of Probability and Statistics and Its Applications before 1750. New York: Wiley. p. 44. ISBN 0471502308. 
  2. ^ Handler, J. G. (1994). Ballentine's Law Dictionary (Legal Assistant ed.). Albany: Delmar. p. 431. ISBN 0827348746. 
  3. ^ Brinegar v. United States, 338 U.S. 160 (1949).
  4. ^ Griffin v. Wisconsin, 483 U.S. 868 (1987).
  5. ^ United States v. Knights, 534 U.S. 112 (2001).
  6. ^ Samson v. California, 547 U.S. 843 (2006).
  7. ^ Koshy, Sunny A. M. (1987–1988), Right of All the People to be Secure: Extending Fundamental Fourth Amendment Rights to Probationers and Parolees, The 39, Hastings L. J., p. 449 
  8. ^ Kneafsey, Sean M. (1994–1995), Fourth Amendment Rights of Probationers: What Remains after Waiving Their Right to be Free from Unreasonable Searches and Seizures, The 35, Santa Clara L. Rev., p. 1237 
  9. ^ Binnall, James M. (2006–2007), They Released Me from My Cage...But They Still Keep Me Handcuffed: A Parolee's Reaction to Samson v. California 4, Ohio St. J. Crim. L., p. 541 
  10. ^ Cacace, Robert (2007), Samson v. California: Tearing down a Pillar of Fourth Amendment Protections 42, Harv. C.R.-C.L. L. Rev., p. 223 
  11. ^ Wallentine, Ken. "The Dog Day Traffic Stop - Basic Canine Search and Seizure." (2008). Web. 21 Oct. 2014.
  12. ^ Illinois v. Gates, 462 U.S. 213 (1983).
  13. ^ Terry v. Ohio, 392 U.S. 1 (1968).
  14. ^ United States v. Matlock, 415 U.S. 164 (1974).
  15. ^ Georgia v. Randolph, 547 U.S. 103 (2006).
  16. ^ FBI web site
  17. ^ New Jersey v. T. L. O., 468 U.S. 1214 (1985).
  18. ^ O'Connor v. Ortega, 480 U.S. 709 (1987).

External links[edit]