Editing Terry stop (section)

===Reasonable suspicion===

{{Further|Reasonable suspicion}}
To possess reasonable suspicion that would justify a stop, police must have "specific and articulable facts" that indicate that the person to be stopped is, or is about to be, engaged in criminal activity. Because officers usually do not have supervision when they encounter civilians, they have discretion regarding whom to stop.<ref name=":56">{{Cite journal|last1=Alpert|first1=Geoffrey P.|last2=Macdonald|first2=John M.|last3=Dunham|first3=Roger G.|title=Police Suspicion and Discretionary Decision Making During Citizen Stops|date=May 2005|url=http://doi.wiley.com/10.1111/j.0011-1348.2005.00012.x|journal=Criminology|language=en|volume=43|issue=2|pages=407–434|doi=10.1111/j.0011-1348.2005.00012.x|issn=0011-1384|url-access=subscription}}</ref> Reasonable suspicion depends on the "[[totality of the circumstances]]".<ref>{{cite journal|last1=Susskind|first1=R.S.|title=Race, Reasonable Articulable Suspicion, and Seizure |journal=American Criminal Law Review |date=1993 |volume=31 |page=327 |url=http://heinonline.org/HOL/LandingPage?handle=hein.journals/amcrimlr31&div=20&id=&page=|access-date=13 November 2018}}</ref> Reasonable suspicion is a vague term, and the Supreme Court concluded that it is to be decided on a case-by-case basis. It often arises from a combination of facts, each of which would, in itself, not be enough justification for the stop.

{| class="wikitable" style="float:left; vertical-align: top; text-align: left; width: 350px; height: 200px; margin:1em 1em 1em 0em;"
! colspan="2" | Types of police-civilian encounters 
|-
! style="vertical-align: top; text-align: left;" | Consensual encounter
| <small>Requires neither probable cause nor reasonable suspicion</small>
|-
! style="background: LightSalmon; vertical-align: top; text-align: left;"| ''Terry'' stop (investigative detention)
| style="vertical-align: top;" | <small>Requires [[reasonable suspicion]]</small>
|-
! style="vertical-align: top; text-align: left;" | Arrest
| style="vertical-align: top;" | <small>Requires [[probable cause]]</small>
|}
The suspicion must be that of an individual person. Police officers primarily use situational factors based on criminal behavior to determine whether a stop is needed. In essence, when they witness a person behaving suspiciously or violating the law, they are constitutionally permitted to stop them. Other factors informing the decision include personal attitudes and the decision-making model in effect where the officer works. These subjective influences naturally create the opportunity for bias on the part of police officers who possess animus toward a certain class of people.<ref name=":56" />

The three types of primary sources that courts should accept in order to determine suspiciousness are information obtained from third parties, information based on the suspect's appearance and behavior and the time and place of the suspected offense. Officers can define what they believe is normal, and if and how the suspect deviates from this.<ref name=":56"/> Reasonable suspicion has been used for actions such as standing in the wrong place, nervousness, exceptional calmness or walking quickly in another direction.<ref name=":16"/> Officers' experiences may make them suspicious of behavior that is usually innocuous.<ref name=":82">{{Cite journal|last1=Cooper|first1=Hannah|last2=Moore|first2=Lisa|last3=Gruskin|first3=Sofia|last4=Krieger|first4=Nancy|date=July 2004|title=Characterizing Perceived Police Violence: Implications for Public Health|journal=American Journal of Public Health|volume=94|issue=7|pages=1109–1118|doi=10.2105/ajph.94.7.1109|issn=0090-0036|pmc=1448406|pmid=15226128}}</ref> For instance, a social interaction such as a hug or a handshake might be perceived as a drug deal.<ref name=":82"/> Merely identifying that a person belongs to a broad category, such as physical location, race, ethnicity or profile, is insufficient for reasonable suspicion. However, stop-and-frisk has been validated on the basis of furtive movements, inappropriate attire, carrying objects such as a television or a pillowcase (in English law, "[[going equipped]]"), vague, nonspecific answers to routine questions, refusal to identify oneself and appearing to be out of place.<ref>{{citation | first1=Kären M. |last1=Hess | first2=Christine Hess |last2=Orthmann | title=Criminal Investigation | edition=9th | year=2010 | page=100}}</ref>

Before 1968, the law required substantial evidence to impede liberty or seize property. However, the Fourth Amendment does not protect consensual encounters. In its ''Terry'' decision, the Supreme Court found that the police should have the power to search, even without probable cause, to protect themselves from weapons.<ref name=":16"/> The ''Terry'' stop operates under the assumption that although stop-and-frisk is an intrusion, the potential harm from weapons outweighs it.<ref name=":25">{{Cite journal|last1=Bandes|first1=Susan A.|last2=Pryor|first2=Marie|last3=Kerrison|first3=Erin M.|last4=Goff|first4=Phillip Atiba|date=March 2019|title=The mismeasure of Terry stops: Assessing the psychological and emotional harms of stop and frisk to individuals and communities|url=https://onlinelibrary.wiley.com/doi/abs/10.1002/bsl.2401|journal=Behavioral Sciences & the Law|language=en|volume=37|issue=2|pages=176–194|doi=10.1002/bsl.2401|pmid=30912171|s2cid=85518215 |issn=0735-3936|url-access=subscription}}</ref>

The cases following ''Terry'' expanded the power of the police. While the original case was concerned with armed violence and firsthand observation by officers, ''Adams v. Williams'' (1972) extended the doctrine to [[drug possession]] substantiated by the secondhand hearsay of an informant.<ref>{{Cite court|litigants=Adams v. Williams|court=2d Cir.|reporter=U.S.|vol=407|opinion=143|date=1972|url=https://supreme.justia.com/cases/federal/us/407/143/|quote=Here, the information from the informant had enough indicia of reliability to justify the officer's forcible stop of petitioner and the protective seizure of the weapon, which afforded reasonable ground for the search incident to the arrest that ensued}}</ref><ref>{{cite journal |last1=Harris |first1=David A. |title=Frisking Every Suspect: The Withering of Terry |journal=UC Davis Law Review |date=1994 |volume=28 |issue=1 |url=https://lawreview.law.ucdavis.edu/issues/28/1/Articles/DavisVol28No1_Harris.pdf}}</ref> The ''Adams v. Williams'' case set a precedent that police are not required to directly observe suspicious behavior if their reasonable suspicion is based upon information provided by a confidential informant.<ref name=":16"/> Regarding the case, Justice Marshall stated: "Today's decision invokes the specter of a society in which innocent citizens may be stopped, searched, and arrested at the whim of police officers who have only the slightest suspicion of improper conduct."<ref name=":16"/> ''United States v. Hensley'' (1985) ruled that police officers may stop and question suspects whom they recognize from "wanted" flyers issued by other police departments.<ref>{{Cite court|litigants=United States v. Hensley|court=6th Cir.|reporter=U.S.|vol=469|opinion=221|date=1985|url=https://supreme.justia.com/cases/federal/us/469/221/|quote=If a 'wanted flyer' has been issued on the basis of articulable facts supporting a reasonable suspicion that the person wanted has committed an offense, then reliance on that flyer justifies a stop to check identification, to pose questions, or to detain the person briefly while attempting to obtain further information}}</ref><ref>{{cite journal |last1=Weiss |first1=Rachel S. |title=Defining the Contours of United States v. Hensley: Limiting the Use of Terry Stops for Completed Misdemeanors |journal=Cornell Law Review |date=2009 |volume=94 |issue=5 |url=https://scholarship.law.cornell.edu/cgi/viewcontent.cgi?article=3146&context=clr}}</ref> In ''[[Illinois v. Wardlow]]'' (2000), a person's unprovoked flight from [[Chicago Police Department|Chicago police officers]] in "an area known for heavy narcotics trafficking" constituted reasonable suspicion to stop him.<ref>{{cite journal |last1=Bernache |first1=Damien |title=The 'High-Crime Area' Question: Requiring Verifiable and Quantifiable Evidence for Fourth Amendment Reasonable Suspicion Analysis |journal=American University Law Review |url=https://digitalcommons.wcl.american.edu/cgi/viewcontent.cgi?referer=https://scholar.google.com/&httpsredir=1&article=1036&context=aulr |date=2008 |volume=57 |issue=6}}</ref>

During ''Terry'' stops, police usually ask detainees to identify themselves. Several states require people to provide their names to the police upon request. In ''[[Hiibel v. Sixth Judicial District Court of Nevada]]'' (2004), these [[stop and identify statutes|stop-and-identify statutes]] were deemed constitutional.<ref>{{cite journal |last1=Nederhood |first1=Robert |title=All or Nothing: The Supreme Court Answers the Question What's in a Name |journal=[[Journal of Criminal Law & Criminology]] |url=https://scholarlycommons.law.northwestern.edu/cgi/viewcontent.cgi?article=7196&context=jclc |date=2005 |volume=95 |issue=3}}</ref> While the specifics of stop-and-identify statutes and ordinances vary, a significant number of states and local jurisdictions have enacted such laws.<ref>{{cite web |title=Stop and Identify Statutes in the United States |url=https://www.ilrc.org/sites/default/files/resources/stop_identify_statutes_in_us-lg-20180201v3.pdf |website=Immigrant Legal Resource Center |access-date=21 April 2021 |date=1 February 2018}}</ref> In New York, courts have limited the effects of ''Terry'' by creating a four-level continuum of intrusion, each of which requires its own level of suspicion.<ref>{{cite web |title=Close Encounters of the Police Kind |url=https://archive.nysba.org/Sections/Criminal_Justice/Criminal_Justice_PDFs/DeBour_Report_2018.html |website=New York State Bar Association |access-date=18 June 2022 |page=1 |format=PDF|archive-url=https://web.archive.org/web/20231027201027/https://archive.nysba.org/Sections/Criminal_Justice/Criminal_Justice_PDFs/DeBour_Report_2018.html|archive-date=October 27, 2023}}</ref> This allows police officers to detain people if the officers possess an articulable and objectively credible reason.<ref>{{cite web | url=https://nycourts.gov/reporter/archives/p_debour.htm | title=People v Ddebour }}</ref> In ''People v. DeBour'', New York's highest court permitted the police to stop a person who simply crosses the street upon observing the police.<ref>{{cite web |author1=[[New York Court of Appeals]] |title=People v De Bour |url=https://nycourts.gov/reporter/archives/p_debour.htm |website=nycourts.gov |access-date=October 27, 2023 |archive-url=https://web.archive.org/web/20231027201259/https://nycourts.gov/reporter/archives/p_debour.htm |archive-date=October 27, 2023 |date=June 15, 1976}}</ref>

Lacking reasonable suspicion, police may stop a person based on a hunch, constituting a [[Stop and identify statutes#Consensual|consensual stop]]. ''[[United States v. Mendenhall]]'' found that police are not generally required to advise an individual that the stop is on a consensual basis nor that the person may leave at any time.<ref> Writing for the court in ''United States v. Mendenhall'', {{ussc|446|544|1980}} [[Potter Stewart|Justice Stewart]] stated,

{{quote|Our conclusion that no seizure occurred is not affected by the fact that the respondent was not expressly told by the agents that she was free to decline to cooperate with their inquiry, for the voluntariness of her responses does not depend upon her having been so informed.|446 U.S. at 555}}</ref> A person can typically determine whether a stop is consensual by asking, "Am I free to go?". If the officer responds in the negative or does not respond, the person is being detained under a ''Terry'' stop; otherwise, the person may leave. ''Mendenhall'' also found that a consensual stop can be converted into an unconstitutional ''Terry'' stop by circumstances such as "the threatening presence of several officers, the display of a weapon by an officer, some physical touching of the person of the citizen, or the use of language or tone of voice indicating that compliance with the officer's request might be compelled." Police who conduct an unconstitutional ''Terry'' stop can face administrative discipline and civil suits.<ref>{{cite news|url=http://www.policemag.com/channel/patrol/articles/2016/02/consensual-encounters.aspx|title=Consensual Encounters|newspaper=Police Magazine|date=5 February 2016 |access-date=16 December 2018}}</ref>

In ''[[Pennsylvania v. Mimms]]'', two police officers issued Mimms a ticket for driving a car with an expired license plate. When they asked him to step out, they realized that he had a gun, and promptly arrested him. The court ruled in favor of the police, citing officer safety as their reason. Dissenting justices found that this furthers the expansion of ''Terry''. They feared that the ruling set a precedent that officers could ask citizens to perform actions through warrantless intrusion.<ref name=":16"/>