Interactions with police officers may be thought of on a continuum, from consensual encounters to a detention, and then to a custodial arrest—in which the officer transports the person for booking into jail. The more that the officer’s actions intrude on the person’s liberty, the more legal justification the officer needs for the intrusion. A consensual encounter is not a seizure. But a detention is a seizure, and if not supported by reasonable suspicion, it may be unreasonable under the Fourth Amendment. Similarly, an arrest is also a seizure, and if not supported by probable cause, it may too be unreasonable under the Fourth Amendment.
In a consensual encounter, provided that the police officer is in a place he or she has a right to be, the officer may approach someone and try question him or her. An example of this would be an officer asking a tenant to “step outside” onto the public sidewalk to question the person about potential involvement in a crime. If the tenant goes outside and agrees to speak with the officer, then the officer needs no other legal justification to continue the encounter.
But a consensual encounter is just that. If at any point the person being questioned tells the officer that she no longer wants to speak or to otherwise cooperate, then the officer must allow her to go on her way. If during the encounter, however, the officer has gotten additional information to justify detaining (or arresting the person), then the consensual encounter has elevated into a detention (or arrest).
Police officers in California are trained, beginning in the police academy, that certain coercive actions may elevate a consensual encounter into a detention and then a detention into an arrest.
For instance, officers know that they could elevate a consensual encounter into a detention by:
All of these actions, in some combination, could elevate a consensual encounter into a non-consensual detention.
The Fourth Amendment protects “the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures.” U.S. Const. Amend. IV. People—including undocumented immigrants—have a Fourth-Amendment right to be free from encounters with police officers. This is among the most sacrosanct of civil liberties, as explained by the United States Supreme Court:
No right is held more sacred, or is more carefully guarded, by the common law, than the right of every individual to the possession and control of his own person, free from all restraint or interference of others, unless by clear and unquestionable authority of law.
Terry v. Ohio, 392 U.S. 1, 9 (1968) (quoting Union Pac. R. Co. v. Botsford, 141 U.S. 250, 251 (1891)).
An investigatory detention occurs when an officer asserts authority so that a “reasonable person” would believe that he or she was not free to leave. A less invasive assertion of authority than a custodial arrest, officers may detain a person to investigate involvement in criminal activity, provided that they have reasonable suspicion at the outset.
California law-enforcement officers are trained that reasonable suspicion is a fact or set of facts that would lead a reasonable officer to believe that criminal activity has taken place, is taking place, or is about to take place, and that the person detained is connected to that criminal activity. An officer bases reasonable suspicion on the “totality of the circumstances” including:
Reasonable suspicion must be “particularized” to the person to be detained. This means that an officer cannot base reasonable suspicion on “racial profiling,” meaning “broad profiles which cast suspicion on entire categories of people without any individualized suspicion of the particular person to be stopped.” United States v. Sigmond-Ballesteros, 285 F.3d 1117, 1121 (9th Cir. 2001). Generally, an investigatory detention is reasonable (and does not violate the Fourth Amendment) if, under all of the circumstances known at the time, the officer had:
During a detention based on reasonable suspicion, and if the person becomes uncooperative, a police officer may use a reasonable amount of force—such as putting on handcuffs, or placing the person into a patrol car—to compel the person to remain. And, if the officer learns other facts to establish probable cause, then the officer may legally arrest the person without violating the Fourth Amendment. But a detention without reasonable suspicion generally violates the Fourth Amendment. Beginning in the police academy, officers are trained that they may be personally liable if they elevate a consensual encounter in which no reasonable suspicion has developed into a detention.
At trial, to prove that an officer unreasonably detained a person, that person must show, more likely than not, that the officer either:
(1) lacked reasonable suspicion to stop the person; or
(2) that the length or scope of the stop was excessive.
Ninth Cir. Civ. Jury Instr. No. 9.21
To prove that the officer lacked reasonable suspicion, and to hold the officer liable, a person must prove either of two negatives. One way to officer liability is by showing that no “particularized and objective basis” existed for the officer to have suspected that the person was involved in criminal activity. Ninth Cir. Civ. Jury Instr. No. 9.21. As discussed above, “particularized” refers to facts specific to that person; for example, reasonable suspicion generally cannot exist based on a person’s merely standing near others suspected of criminal activity.
In assessing reasonable suspicion, officers are allowed to draw upon their own experience and specialized training to make inferences from, and deductions about, all of the facts that the particular encounter presents them with. Ninth Cir. Civ. Jury Instr. No. 9.21. Therefore, they may cite their “training and experience” to add more “facts” to the group of facts leading to reasonable suspicion. But an officer may not base reasonable suspicion on particularized facts to the person to be detained.
The second way to officer liability involves proving that the length or scope of the stop was excessive, making it an unreasonable seizure. Through intrusive police actions, an otherwise reasonable detention supported by reasonable suspicion may turn into an unreasonable arrest lacking probable cause. At trial, the judge will instruct the jury to consider all of the circumstances of the incident, including:
(1) the intrusiveness of the stop, such as the methods the police used, the restriction on the plaintiff’s liberty, and the length of the stop;
(2) whether the methods used were reasonable under the circumstances; and
(3) other factors applicable to the particular case.
Ninth Cir. Civ. Jury Instr. No. 9.21
Generally, to prevail at trial, a person will need to show the jury that the officer’s use of force or other coercion made the detention unreasonable.
Generally, police officers may detain people in the immediate vicinity of a location—including occupants of a home—while executing a valid search warrant of that place. To prove an unreasonable detention by police during the execution of a search warrant, a person must prove that the police detained her in an unreasonable manner or for an unreasonable period of time (or both). Ninth Cir. Civ. Jury Instr. No. 9.24
To determine whether the detention was unreasonable, a jury will consider all of the circumstances known to the officer on the scene, including:
For example, a jury could find that a detention was unreasonable in which officers–who had already searched an innocuous-looking twelve-year-old-looking boy for weapons while holding a gun to his head–handcuffed the boy for 15 to 20 more minutes, and then allegedly lifted him from behind by the chain of the handcuffs (among other conduct). Tekle v. United States, 511 F.3d 839, 850 (9th Cir. 2006).
Generally, if an officer arrested someone without a warrant, then to prove that the arrest was unreasonable, the person arrested must prove, more likely than not, that the officer arrested her without probable cause. Ninth Cir. Civ. Jury Instr. No. 9.23.
Warrantless arrests not based on probable cause violate the Fourth Amendment. Probable cause is a set of facts that would cause a reasonably careful and prudent person to have an honest and strong belief that the person to be arrested is guilty of a crime. An officer may base probable cause on many kinds of facts, derived for example from:
In considering whether probable cause exists to arrest, the law expects officers to be “reasonable and prudent men [and women], not legal technicians.” Brinegar v. United States, 338 U.S. 160, 175 (1949). An officer, however, must base probable cause on objective facts. “Mere suspicion, common rumor, or even strong reason to suspect are not enough[.]” McKenzie v. Lamb, 738 F.2d 1005, 1008 (9th Cir. 1984) (citation omitted). Like reasonable suspicion, probable cause must be particularized to the person to be arrested.
Probable cause does not take into account the arresting officer’s subjective beliefs about the crime the officer thought about arresting for. Because the officer’s subjective intent doesn’t matter, probable cause may exist to arrest for any crime, even if the arresting officer wasn’t thinking about that particular crime when arresting. Even if an officer mistakenly thought she had probable cause to arrest a person for a certain crime, if the facts would lead a reasonable officer to conclude that probable cause existed for any other crime—even one the arresting officer was not thinking of—then the arrest does not violate the Fourth Amendment.
Criminal laws are composed of elements, and to obtain a conviction at trial, the prosecution must prove to a jury, beyond a reasonable doubt, every element. But officers in the field, who are often making on-the-spot determinations in real time, do not have to be able to articulate facts going to every element of a particular criminal offense before arresting a person. The law holds officers in the field to a lower standard: “[p]robable cause does not require the same type of specific evidence of each element of the offense as would be needed to support a conviction.” Adams v. Williams, 407 U.S. 143, 149 (1971).
So, an officer does not need probable cause for every element of the crime—unless the crime involves “specific intent,” in which case the officer must have probable cause, or facts, tending to prove that element.
In a Fourth Amendment false-arrest claim, probable cause is for the jury to determine: where “reasonable persons might reach different conclusions about the facts, the establishment of those facts is for the jury, and the existence of probable cause is likewise for the jury, upon a proper instruction about the law.” If no reasonable jury could find that the officers did or did not have probable cause to arrest, then the court may determine the existence of probable cause as a matter of law. McKenzie, 738 F.2d at 1008.
If an officer has probable cause to arrest someone for a very minor crime, then the officer may arrest and transport that person to jail for booking without violating the Fourth Amendment. The United States Supreme Court has ruled that if “an officer has probable cause to believe that an individual has committed even a very minor criminal offense in his presence, he may, without violating the Fourth Amendment, arrest the offender.” Atwater v. City of Lago Vista, 532 U.S. 318, 354 (2001).
For example, and as the Supreme Court held in Atwater v. City of Lago Vista, if state law requires wearing a seatbelt while driving, and a police officer sees a person not wearing one while driving, the officer may arrest the person and transport her for booking at a jail—without violating the Fourth Amendment.