Document ID: ./input/supremecourt_opinions/opinions/17pdf/16-402_h315.pdf
Page Number: 7.0

Cite as:  585 U. S. ____ (2018) 

3 

Opinion of the Court 

robberies. 

Based  on  that  information,  the  prosecutors  applied  for 
court  orders  under  the  Stored  Communications  Act  to 
obtain cell phone records for petitioner Timothy Carpenter
and  several  other  suspects.  That  statute,  as  amended  in 
1994, permits the Government to compel the disclosure of
certain telecommunications records when it “offers specific
and  articulable  facts  showing  that  there  are  reasonable 
grounds  to  believe”  that  the  records  sought  “are  relevant 
and  material  to  an  ongoing  criminal  investigation.”    18 
U. S. C.  §2703(d).    Federal  Magistrate  Judges  issued  two
orders  directing  Carpenter’s  wireless  carriers—MetroPCS
and  Sprint—to  disclose  “cell/site  sector  [information]  for 
[Carpenter’s]  telephone[ ]  at  call  origination  and  at  call
termination  for  incoming  and  outgoing  calls”  during  the
four-month  period  when  the  string  of  robberies  occurred.
App. to Pet. for Cert. 60a, 72a.  The first order sought 152
days  of  cell-site  records  from  MetroPCS,  which  produced
records  spanning  127  days.    The  second  order  requested 
seven days of CSLI from Sprint, which produced two days
of records covering the period when Carpenter’s phone was 
“roaming”  in  northeastern  Ohio.    Altogether  the  Govern-
ment  obtained  12,898  location  points  cataloging  Carpen-
ter’s movements—an average of 101 data points per day.

Carpenter  was  charged  with  six  counts  of  robbery  and
an  additional  six  counts  of  carrying  a  firearm  during  a
federal crime of violence.  See 18 U. S. C. §§924(c), 1951(a).
Prior  to  trial,  Carpenter  moved  to  suppress  the  cell-site 
data provided by the wireless carriers.  He argued that the
Government’s  seizure  of  the  records  violated  the  Fourth 
Amendment  because  they  had  been  obtained  without  a 
warrant supported by probable cause.  The District Court 
denied the motion.  App. to Pet. for Cert. 38a–39a. 

At  trial,  seven  of  Carpenter’s  confederates  pegged  him
as  the  leader  of  the  operation.  In  addition,  FBI  agent
Christopher  Hess  offered  expert  testimony  about  the  cell-