Task: sc_petitioner

What follows is an opinion from the Supreme Court of the United States. Your task is to identify the petitioner of the case. The petitioner is the party who petitioned the Supreme Court to review the case. This party is variously known as the petitioner or the appellant. Characterize the petitioner as the Court's opinion identifies them.

Identify the petitioner by the label given to the party in the opinion or judgment of the Court except where the Reports title a party as the "United States" or as a named state. Textual identification of parties is typically provided prior to Part I of the Court's opinion. The official syllabus, the summary that appears on the title page of the case, may be consulted as well. In describing the parties, the Court employs terminology that places them in the context of the specific lawsuit in which they are involved. For example, "employer" rather than "business" in a suit by an employee; as a "minority," "female," or "minority female" employee rather than "employee" in a suit alleging discrimination by an employer.

Also note that the Court's characterization of the parties applies whether the petitioner is actually single entity or whether many other persons or legal entities have associated themselves with the lawsuit. That is, the presence of the phrase, et al., following the name of a party does not preclude the Court from characterizing that party as though it were a single entity. Thus, identify a single petitioner, regardless of how many legal entities were actually involved. If a state (or one of its subdivisions) is a party, note only that a state is a party, not the state's name.

Chief Justice Roberts
delivered the opinion of the Court.
In this case we consider whether police may enter a home without a warrant when they have an objectively reasonable basis for believing that an occupant is seriously injured or imminently threatened with such injury. We conclude that they may.
I
This case arises out of a melee that occurred in a Brigham City, Utah, home in the early morning hours of July 23, 2000. At about 3 a.m., four police officers responded to a call regarding a loud party at a residence. Upon arriving at the house, they heard shouting from inside, and proceeded down the driveway to investigate. There, they observed two juveniles drinking beer in the backyard. They entered the backyard, and saw — through a screen door and windows — an altercation taking place in the kitchen of the home. According to the testimony of one of the officers, four adults were attempting, with some difficulty, to restrain a juvenile. The juvenile eventually “broke free, swung a fist and struck one of the adults in the face.” 2005 UT 13, ¶ 2, 122 P. 3d 506, 508. The officer testified that he observed the victim of the blow spitting blood into a nearby sink. App. 40. The other adults continued to try to restrain the juvenile, pressing him up against a refrigerator with such force that the refrigerator began moving across the floor. At this point, an officer opened the screen door and announced the officers’ presence. Amid the tumult, nobody noticed. The officer entered the kitchen and again cried out, and as the occupants slowly became aware that the police were on the scene, the altercation ceased.
The officers subsequently arrested respondents and charged them with contributing to the delinquency of a minor, disorderly conduct, and intoxication. In the trial court, respondents filed a motion to suppress all evidence obtained after the officers entered the home, arguing that the warrantless entry violated the Fourth Amendment. The court granted the motion, and the Utah Court of Appeals affirmed.
Before the Supreme Court of Utah, Brigham City argued that although the officers lacked a warrant, their entry was nevertheless reasonable on either of two grounds. The court rejected both contentions and, over two dissenters, affirmed. First, the court held that the injury caused by the juvenile’s punch was insufficient to trigger the so-called “emergency aid doctrine” because it did not give rise to an “objectively reasonable belief that an unconscious, semiconscious, or missing person feared injured or dead [was] in the home.” 122 P. 3d, at 513 (internal quotation marks omitted). Furthermore, the court suggested that the doctrine was inapplicable because the officers had not sought to assist the injured adult, but instead had acted “exclusively in their law enforcement capacity.” Ibid.
The court also held that the entry did not fall within the exigent circumstances exception to the warrant requirement. This exception applies, the court explained, where police have probable cause and where “a reasonable person [would] believe that the entry was necessary to prevent physical harm to the officers or other persons.” Id., at 514 (internal quotation marks omitted). Under this standard, the court stated, the potential harm need not be as serious as that required to invoke the emergency aid exception. Although it found the case “a close and difficult call,” the court nevertheless concluded that the officers’ entry was not justified by exigent circumstances. Id., at 515.
We granted certiorari, 546 U. S. 1085 (2006), in light of differences among state courts and the Courts of Appeals concerning the appropriate Fourth Amendment standard governing warrantless entry by law enforcement in an emergency situation. Compare In re Sealed Case 96-3167, 153 F. 3d 759, 766 (CADC 1998) (“[T]he standard for exigent circumstances is an objective one”), and People v. Hebert, 46 P. 3d 473, 480 (Colo. 2002) (en banc) (considering the circumstances as they “would have been objectively examined by a prudent and trained police officer”), with United States v. Cervantes, 219 F. 3d 882, 890 (CA9 2000) (“[U]nder the emergency doctrine, ‘[a] search must not be primarily motivated by intent to arrest and seize evidence’” (quoting People v. Mitchell, 39 N. Y. 2d 173, 177, 347 N. E. 2d 607, 609 (1976)), and State v. Mountford, 171 Vt. 487, 492, 769 A. 2d 639, 645 (2000) (Mitchell test “requires] courts to find that the primary subjective motivation behind such searches was to provide emergency aid”).
II
It is a “‘basic principle of Fourth Amendment law that searches and seizures inside a home without a warrant are presumptively unreasonable.’ ” Groh v. Ramirez, 540 U. S. 551, 559 (2004) (quoting Payton v. New York, 445 U. S. 573, 586 (1980); some internal quotation marks omitted). Nevertheless, because the ultimate touchstone of the Fourth Amendment is “reasonableness,” the warrant requirement is subject to certain exceptions. Flippo v. West Virginia, 528 U. S. 11, 13 (1999) (per curiam); Katz v. United States, 389 U. S. 347, 357 (1967). We have held, for example, that law enforcement officers may make a warrantless entry onto private property to fight a fire and investigate its cause, Michigan v. Tyler, 436 U. S. 499, 509 (1978), to prevent the imminent destruction of evidence, Ker v. California, 374 U. S. 23, 40 (1963) (plurality opinion), or to engage in “ ‘hot pursuit’ ” of a fleeing suspect, United States v. Santana, 427 U. S. 38, 42, 43 (1976). “[Wjarrants are generally required to search a person’s home or his person unless ‘the exigencies of the situation’ make the needs of law enforcement so compelling that the warrantless search is objectively reasonable under the Fourth Amendment.” Mincey v. Arizona, 437 U. S. 385, 393-394 (1978).
One exigency obviating the requirement of a warrant is the need to assist persons who are seriously injured or threatened with such injury. “ ‘The need to protect or preserve life or avoid serious injury is justification for what would be otherwise illegal absent an exigency or emergency.’” Id., at 392 (quoting Wayne v. United States, 318 F. 2d 205, 212 (CADC 1963) (Burger, J.)); see also Tyler, supra, at 509. Accordingly, law enforcement officers may enter a home without a warrant to render emergency assistance to an injured occupant or to protect an occupant from imminent injury. Mincey, supra, at 392; see also Georgia v. Randolph, ante, at 118 (“[I]t would be silly to suggest that the police would commit a tort by entering ... to determine whether violence (or threat of violence) has just occurred or is about to (or soon will) occur”).
Respondents do not take issue with these principles, but instead advance two reasons why the officers’ entry here was unreasonable. First, they argue that the officers were more interested in making arrests than quelling violence. They urge us to consider, in assessing the reasonableness of the entry, whether the officers were “indeed motivated primarily by a desire to save lives and property.” Brief for Respondents 3; see also Brief for National Association of Criminal Defense Lawyers as Amicus Curiae 6 (entry to render emergency assistance justifies a search “only when the searching officer is acting outside his traditional law-enforcement capacity”). The Utah Supreme Court also considered the officers’ subjective motivations relevant. See 122 P. 3d, at 513 (search under the “emergency aid doctrine” may not be “primarily motivated by intent to arrest and seize evidence” (internal quotation marks omitted)).
Our cases have repeatedly rejected this approach. An action is “reasonable” under the Fourth Amendment, regardless of the individual officer’s state of mind, “as long as the circumstances, viewed objectively, justify [the] action.” Scott v. United States, 436 U. S. 128, 138 (1978) (emphasis added). The officer’s subjective motivation is irrelevant. See Bond v. United States, 529 U. S. 334, 338, n. 2 (2000) (“The parties properly agree that the subjective intent of the law enforcement officer is irrelevant in determining whether that officer’s actions violate the Fourth Amendment...; the issue is not his state of mind, but the objective effect of his actions”); Whren v. United States, 517 U. S. 806, 813 (1996) (“[W]e have been unwilling to entertain Fourth Amendment challenges based on the actual motivations of individual officers”); Graham v. Connor, 490 U. S. 386, 397 (1989) (“[0]ur prior cases make clear” that “the subjective motivations of the individual officers . . . ha[ve] no bearing on whether a particular seizure is ‘unreasonable’ under the Fourth Amendment”). It therefore does not matter here — even if their subjective motives could be so neatly unraveled — whether the officers entered the kitchen to arrest respondents and gather evidence against them or to assist the injured and prevent further violence.
As respondents note, we have held in the context of programmatic searches conducted without individualized suspicion — such as checkpoints to combat drunk driving or drug trafficking — that “an inquiry into programmatic purpose” is sometimes appropriate. Indianapolis v. Edmond, 531 U. S. 32, 46 (2000) (emphasis added); see also Florida v. Wells, 495 U. S. 1, 4 (1990) (an inventory search must be regulated by “standardized criteria” or “established routine” so as not to “be a ruse for a general rummaging in order to discover incriminating evidence”). But this inquiry is directed at ensuring that the purpose behind the program is not “ultimately indistinguishable from the general interest in crime control.” Edmond, 531 U. S., at 44. It has nothing to do with discerning what is in the mind of the individual officer conducting the search. Id., at 48.
Respondents further contend that their conduct was not serious enough to justify the officers’ intrusion into the home. They rely on Welsh v. Wisconsin, 466 U. S. 740, 753 (1984), in which we held that “an important factor to be considered when determining whether any exigency exists is the gravity of the underlying offense for which the arrest is being made.” This contention, too, is misplaced. Welsh involved a warrantless entry by officers to arrest a suspect for driving while intoxicated. There, the “only potential emergency” confronting the officers was the' need to preserve evidence (i. e., the suspect’s blood-alcohol level) — an exigency that we held insufficient under the circumstances to justify entry into the suspect’s home. Ibid. Here, the officers were confronted with ongoing violence occurring within the home. Welsh did not address such a situation.
We think the officers’ entry here was plainly reasonable under the circumstances. The officers were responding, at 3 o’clock in the morning, to complaints about a loud party. As they approached the house, they could hear from within “an altercation occurring, some kind of a fight.” App. 29. “It was loud and it was tumultuous.” Id., at 33. The officers heard “thumping and crashing” and people yelling “stop, stop” and “get off me.” Id., at 28, 29. As the trial court found, “it was obvious that . . . knocking on the front door” would have been futile. Id., at 92. The noise seemed to be coming from the back of the house; after looking in the front window and seeing nothing, the officers proceeded around back to investigate further. They found two juveniles drinking beer in the backyard. From there, they could see that a fracas was taking place inside the kitchen. A juvenile, fists clenched, was being held back by several adults. As the officers watch, he breaks free and strikes one of the adults in the face, sending the adult to the sink spitting blood.
In these circumstances, the officers had an objectively reasonable basis for believing both that the injured adult might need help and that the violence in the kitchen was just beginning. Nothing in the Fourth Amendment required them to wait until another blow rendered someone “unconscious” or “semi-conscious” or worse before entering. The role of a peace officer includes preventing violence and restoring order, not simply rendering first aid to casualties; an officer is not like a boxing (or hockey) referee, poised to stop a bout only if it becomes too one-sided.
The manner of the officers’ entry was also reasonable. After witnessing the punch, one of the officers opened the screen door and “yelled in police.” Id., at 40. When nobody heard him, he stepped into the kitchen and announced himself again. Only then did the tumult subside. The officer’s announcement of his presence was at least equivalent to a knock on the screen door. Indeed, it was probably the only option that had even a chance of rising above the din. Under these circumstances, there was no violation of the Fourth Amendment’s knock-and-announce rule. Furthermore, once the announcement was made, the officers were free to enter; it would serve no purpose to require them to stand dumbly at the door awaiting a response while those within brawled on, oblivious to their presence.
Accordingly, we reverse the judgment of the Supreme Court of Utah, and remand the case for further proceedings not inconsistent with this opinion.
It is so ordered.

Question: Who is the petitioner of the case?
年. attorney general of the United States, or his office
数. specified state board or department of education
日. city, town, township, village, or borough government or governmental unit
的. state commission, board, committee, or authority
月. county government or county governmental unit, except school district
用. court or judicial district
成. state department or agency
名. governmental employee or job applicant
时. female governmental employee or job applicant
件. minority governmental employee or job applicant
一. minority female governmental employee or job applicant
请. not listed among agencies in the first Administrative Action variable
中. retired or former governmental employee
据. U.S. House of Representatives
码. interstate compact
不. judge
新. state legislature, house, or committee
文. local governmental unit other than a county, city, town, township, village, or borough
下. governmental official, or an official of an agency established under an interstate compact
分. state or U.S. supreme court
入. local school district or board of education
人. U.S. Senate
功. U.S. senator
上. foreign nation or instrumentality
户. state or local governmental taxpayer, or executor of the estate of
为. state college or university
间. United States
号. State
取. person accused, indicted, or suspected of crime
回. advertising business or agency
在. agent, fiduciary, trustee, or executor
页. airplane manufacturer, or manufacturer of parts of airplanes
字. airline
有. distributor, importer, or exporter of alcoholic beverages
个. alien, person subject to a denaturalization proceeding, or one whose citizenship is revoked
作. American Medical Association
示. National Railroad Passenger Corp.
出. amusement establishment, or recreational facility
是. arrested person, or pretrial detainee
失. attorney, or person acting as such;includes bar applicant or law student, or law firm or bar association
表. author, copyright holder
除. bank, savings and loan, credit union, investment company
加. bankrupt person or business, or business in reorganization
败. establishment serving liquor by the glass, or package liquor store
生. water transportation, stevedore
信. bookstore, newsstand, printer, bindery, purveyor or distributor of books or magazines
类. brewery, distillery
置. broker, stock exchange, investment or securities firm
理. construction industry
本. bus or motorized passenger transportation vehicle
息. business, corporation
行. buyer, purchaser
定. cable TV
改. car dealer
市. person convicted of crime
期. tangible property, other than real estate, including contraband
以. chemical company
修. child, children, including adopted or illegitimate
元. religious organization, institution, or person
方. private club or facility
录. coal company or coal mine operator
区. computer business or manufacturer, hardware or software
单. consumer, consumer organization
位. creditor, including institution appearing as such; e.g., a finance company
型. person allegedly criminally insane or mentally incompetent to stand trial
法. defendant
县. debtor
存. real estate developer
品. disabled person or disability benefit claimant
前. distributor
称. person subject to selective service, including conscientious objector
注. drug manufacturer
值. druggist, pharmacist, pharmacy
输. employee, or job applicant, including beneficiaries of
建. employer-employee trust agreement, employee health and welfare fund, or multi-employer pension plan
能. electric equipment manufacturer
大. electric or hydroelectric power utility, power cooperative, or gas and electric company
例. eleemosynary institution or person
度. environmental organization
始. employer. If employer's relations with employees are governed by the nature of the employer's business (e.g., railroad, boat), rather than labor law generally, the more specific designation is used in place of Employer.
到. farmer, farm worker, or farm organization
面. father
载. female employee or job applicant
点. female
密. movie, play, pictorial representation, theatrical production, actor, or exhibitor or distributor of
动. fisherman or fishing company
果. food, meat packing, or processing company, stockyard
图. foreign (non-American) nongovernmental entity
提. franchiser
发. franchisee
式. lesbian, gay, bisexual, transexual person or organization
国. person who guarantees another's obligations
登. handicapped individual, or organization of devoted to
错. health organization or person, nursing home, medical clinic or laboratory, chiropractor
者. heir, or beneficiary, or person so claiming to be
认. hospital, medical center
误. husband, or ex-husband
接. involuntarily committed mental patient
关. Indian, including Indian tribe or nation
重. insurance company, or surety
第. inventor, patent assigner, trademark owner or holder
地. investor
如. injured person or legal entity, nonphysically and non-employment related
设. juvenile
目. government contractor
开. holder of a license or permit, or applicant therefor
事. magazine
可. male
要. medical or Medicaid claimant
代. medical supply or manufacturing co.
小. racial or ethnic minority employee or job applicant
选. minority female employee or job applicant
标. manufacturer
明. management, executive officer, or director, of business entity
编. military personnel, or dependent of, including reservist
求. mining company or miner, excluding coal, oil, or pipeline company
列. mother
网. auto manufacturer
万. newspaper, newsletter, journal of opinion, news service
最. radio and television network, except cable tv
器. nonprofit organization or business
所. nonresident
内. nuclear power plant or facility
体. owner, landlord, or claimant to ownership, fee interest, or possession of land as well as chattels
通. shareholders to whom a tender offer is made
务. tender offer
此. oil company, or natural gas producer
商. elderly person, or organization dedicated to the elderly
序. out of state noncriminal defendant
化. political action committee
消. parent or parents
否. parking lot or service
保. patient of a health professional
使. telephone, telecommunications, or telegraph company
次. physician, MD or DO, dentist, or medical society
机. public interest organization
对. physically injured person, including wrongful death, who is not an employee
量. pipe line company
查. package, luggage, container
部. political candidate, activist, committee, party, party member, organization, or elected official
性. indigent, needy, welfare recipient
和. indigent defendant
更. private person
后. prisoner, inmate of penal institution
证. professional organization, business, or person
题. probationer, or parolee
确. protester, demonstrator, picketer or pamphleteer (non-employment related), or non-indigent loiterer
格. public utility
了. publisher, publishing company
于. radio station
金. racial or ethnic minority
公. person or organization protesting racial or ethnic segregation or discrimination
午. racial or ethnic minority student or applicant for admission to an educational institution
円. realtor
片. journalist, columnist, member of the news media
空. resident
态. restaurant, food vendor
管. retarded person, or mental incompetent
主. retired or former employee
天. railroad
自. private school, college, or university
我. seller or vendor
全. shipper, including importer and exporter
今. shopping center, mall
来. spouse, or former spouse
正. stockholder, shareholder, or bondholder
说. retail business or outlet
意. student, or applicant for admission to an educational institution
送. taxpayer or executor of taxpayer's estate, federal only
容. tenant or lessee
已. theater, studio
结. forest products, lumber, or logging company
会. person traveling or wishing to travel abroad, or overseas travel agent
段. trucking company, or motor carrier
计. television station
源. union member
色. unemployed person or unemployment compensation applicant or claimant
時. union, labor organization, or official of
交. veteran
系. voter, prospective voter, elector, or a nonelective official seeking reapportionment or redistricting of legislative districts (POL)
过. wholesale trade
电. wife, or ex-wife
询. witness, or person under subpoena
符. network
未. slave
程. slave-owner
常. bank of the united states
条. timber company
当. u.s. job applicants or employees
情. Army and Air Force Exchange Service
口. Atomic Energy Commission
合. Secretary or administrative unit or personnel of the U.S. Air Force
车. Department or Secretary of Agriculture
实. Alien Property Custodian
组. Secretary or administrative unit or personnel of the U.S. Army
版. Board of Immigration Appeals
周. Bureau of Indian Affairs
址. Bonneville Power Administration
记. Benefits Review Board
二. Civil Aeronautics Board
同. Bureau of the Census
业. Central Intelligence Agency
权. Commodity Futures Trading Commission
其. Department or Secretary of Commerce
进. Comptroller of Currency
试. Consumer Product Safety Commission
验. Civil Rights Commission
料. Civil Service Commission, U.S.
传. Customs Service or Commissioner of Customs
述. Defense Base Closure and REalignment Commission
集. Drug Enforcement Agency
多. Department or Secretary of Defense (and Department or Secretary of War)
无. Department or Secretary of Energy
员. Department or Secretary of the Interior
报. Department of Justice or Attorney General
他. Department or Secretary of State
無. Department or Secretary of Transportation
服. Department or Secretary of Education
线. U.S. Employees' Compensation Commission, or Commissioner
这. Equal Employment Opportunity Commission
制. Environmental Protection Agency or Administrator
将. Federal Aviation Agency or Administration
处. Federal Bureau of Investigation or Director
高. Federal Bureau of Prisons
子. Farm Credit Administration
道. Federal Communications Commission (including a predecessor, Federal Radio Commission)
章. Federal Credit Union Administration
手. Food and Drug Administration
库. Federal Deposit Insurance Corporation
三. Federal Energy Administration
从. Federal Election Commission
支. Federal Energy Regulatory Commission
家. Federal Housing Administration
长. Federal Home Loan Bank Board
付. Federal Labor Relations Authority
秒. Federal Maritime Board
路. Federal Maritime Commission
完. Farmers Home Administration
象. Federal Parole Board
则. Federal Power Commission
现. Federal Railroad Administration
京. Federal Reserve Board of Governors
转. Federal Reserve System
辑. Federal Savings and Loan Insurance Corporation
限. Federal Trade Commission
力. Federal Works Administration, or Administrator
学. General Accounting Office
外. Comptroller General
调. General Services Administration
项. Department or Secretary of Health, Education and Welfare
北. Department or Secretary of Health and Human Services
工. Department or Secretary of Housing and Urban Development
笑. Interstate Commerce Commission
监. Indian Claims Commission
任. Immigration and Naturalization Service, or Director of, or District Director of, or Immigration and Naturalization Enforcement
相. Internal Revenue Service, Collector, Commissioner, or District Director of
微. Information Security Oversight Office
册. Department or Secretary of Labor
联. Loyalty Review Board
平. Legal Services Corporation
增. Merit Systems Protection Board
听. Multistate Tax Commission
解. National Aeronautics and Space Administration
等. Secretary or administrative unit of the U.S. Navy
得. National Credit Union Administration
收. National Endowment for the Arts
安. National Enforcement Commission
价. National Highway Traffic Safety Administration
藏. National Labor Relations Board, or regional office or officer
命. National Mediation Board
应. National Railroad Adjustment Board
看. Nuclear Regulatory Commission
索. National Security Agency
资. Office of Economic Opportunity
产. Office of Management and Budget
串. Office of Price Administration, or Price Administrator
布. Office of Personnel Management
原. Occupational Safety and Health Administration
知. Occupational Safety and Health Review Commission
级. Office of Workers' Compensation Programs
水. Patent Office, or Commissioner of, or Board of Appeals of
击. Pay Board (established under the Economic Stabilization Act of 1970)
好. Pension Benefit Guaranty Corporation
物. U.S. Public Health Service
放. Postal Rate Commission
亿. Provider Reimbursement Review Board
经. Renegotiation Board
模. Railroad Adjustment Board
之. Railroad Retirement Board
台. Subversive Activities Control Board
州. Small Business Administration
配. Securities and Exchange Commission
画. Social Security Administration or Commissioner
统. Selective Service System
共. Department or Secretary of the Treasury
连. Tennessee Valley Authority
海. United States Forest Service
节. United States Parole Commission
退. Postal Service and Post Office, or Postmaster General, or Postmaster
間. United States Sentencing Commission
比. Veterans' Administration
问. War Production Board
至. Wage Stabilization Board
备. General Land Office of Commissioners
你. Transportation Security Administration
黑. Surface Transportation Board
或. U.S. Shipping Board Emergency Fleet Corp.
与. Reconstruction Finance Corp.
影. Department or Secretary of Homeland Security
话. Unidentifiable
视. International Entity
Answer:

Answer: 日