Document ID: ./input/supremecourt_opinions/opinions/12pdf/11-1425_cb8e.pdf
Page Number: 31.0

2 

MISSOURI v. MCNEELY 

Opinion of ROBERTS, C. J. 

the blood may be drawn without a warrant. 

The Fourth Amendment provides: 

I 

“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,  sup-
ported  by  Oath  or  affirmation,  and  particularly  de-
scribing  the  place  to  be  searched,  and  the  persons  or 
things to be seized.” 

That  language  does  not  state  that  warrants  are  required 
prior  to  searches,  but  this  Court  has  long  held  that  war-
rants  must  generally  be  obtained.    See  Kentucky  v.  King, 
563 U. S. ___, ___ (2011) (slip op., at 5).  We have also held 
that bodily intrusions like blood draws constitute searches 
  See 
and  are  subject  to  the  warrant  requirement. 
Schmerber v. California, 384 U. S. 757, 767, 770 (1966). 

However,  “the  ultimate  touchstone  of  the  Fourth 
Amendment  is  ‘reasonableness,’ ”  Brigham  City  v.  Stuart, 
547 U. S. 398, 403 (2006), and thus “the warrant require-
ment  is  subject  to  certain  reasonable  exceptions,”  King, 
563 U. S., at ___ (slip op., at 6).  One of those exceptions is
known  as  the  “exigent  circumstances  exception,”  which
“applies  when  the  exigencies  of  the  situation  make  the 
needs of law enforcement so compelling that a warrantless
search 
is  objectively  reasonable  under  the  Fourth 
Amendment.”  Ibid. (internal quotation marks and altera-
tions omitted).

Within  the  exigent  circumstances  exception,  we  have 
identified  several  sets  of  exigent  circumstances  excusing 
the need for a warrant.  For example, there is an emergency 
aid  exception  to  the  warrant  requirement.    In  Brigham 
City, supra, at 403, we held that “law enforcement officers 
may enter a home without a warrant to render emergency