Document ID: ./input/supremecourt_opinions/opinions/boundvolumes/558bv.pdf
Page Number: 208

Cite as: 558 U. S. 45 (2009) 

47 

Per Curiam 

See  483  Mich.  1007,  765  N.  W.  2d  19  (2009).  Because  the 
decision of the Michigan Court of Appeals is indeed contrary 
to  our  Fourth  Amendment  case  law,  particularly  Brigham 
City v.  Stuart, 547 U. S. 398 (2006), we grant the State’s peti­
tion for certiorari and reverse. 

“[T]he ultimate touchstone of the Fourth Amendment,” we 
have  often  said,  “is  ‘reasonableness.’ ”  Id.,  at  403.  There­
fore,  although  “searches  and  seizures inside  a  home  without 
a  warrant  are  presumptively  unreasonable,”  Groh  v.  Rami­
rez, 540 U. S. 551, 559 (2004) (internal quotation marks omit­
ted), that presumption can be overcome.  For example, “the 
exigencies  of  the  situation  [may]  make  the  needs  of  law 
enforcement so compelling that the warrantless search is ob­
jectively  reasonable.”  Mincey  v.  Arizona,  437  U. S.  385, 
393–394 (1978) (internal quotation marks omitted). 

Brigham  City  identiﬁed  one  such  exigency:  “the  need  to 
assist  persons  who  are  seriously  injured  or  threatened  with 
such  injury.”  547  U. S.,  at  403.  Thus,  law  enforcement  of­
ﬁcers “may enter a home without a warrant to render emer­
gency assistance to an injured occupant or to protect an occu­
pant  from  imminent  injury.”  Ibid.  This  “emergency  aid 
exception” does not depend on the ofﬁcers’ subjective intent 
or the seriousness of any crime they are investigating when 
the emergency arises.  Id., at 404–405.  It requires only “an 
objectively  reasonable  basis  for  believing,”  id.,  at  406,  that 
“a  person  within  [the  house]  is  in  need  of  immediate  aid,” 
Mincey, supra, at 392. 

Brigham  City  illustrates  the  application  of  this  standard. 
There,  police  ofﬁcers  responded  to  a  noise  complaint  in  the 
early hours of the morning.  “As they approached the house, 
they  could  hear  from  within  an  altercation  occurring,  some 
kind  of  ﬁght.”  547  U. S.,  at  406  (internal  quotation  marks 
omitted).  Following  the  tumult  to  the  back  of  the  house 
whence  it  came,  the  ofﬁcers  saw  juveniles  drinking  beer  in 
the  backyard  and  a  ﬁght  unfolding  in  the  kitchen.  They