Document ID: ./input/supremecourt_opinions/opinions/10pdf/09-1233.pdf
Page Number: 5

Cite as:  563 U. S. ____ (2011) 

5 

Syllabus 

results, some facilities may retain populations in excess of the 137.5%
limit  provided  others  fall  sufficiently  below  it  so  the  system  as  a
whole  remains  in  compliance  with  the  order.    This  will  afford  the 
State  flexibility  to  accommodate  differences  between  institutions.
The order may shape or control the State’s authority in the realm of
prison  administration,  but  it  leaves  much  to  the  State’s  discretion. 
The order’s limited scope is necessary to remedy a constitutional vio-
lation.  The State may move the three-judge court to modify its order, 
but  it  has  proposed  no  realistic  alternative  remedy  at  this  time.
Pp. 33–36. 

(2) The  three-judge  court  gave  “substantial  weight”  to  any  po-
tential  adverse  impact  on  public  safety  from  its  order.    The  PLRA’s 
“substantial weight” requirement does not require the court to certify
that  its  order  has  no  possible  adverse  impact  on  the  public.    Here, 
statistical evidence showed that prison populations had been lowered
without adversely affecting public safety in some California counties,
several  States,  and  Canada.    The  court  found  that  various  available 
methods  of  reducing  overcrowding—good  time  credits  and  diverting
low-risk  offenders  to  community  programs—would  have  little  or  no 
impact  on  public  safety,  and  its  order  took  account  of  such  concerns
by giving the State substantial flexibility to select among the means
of  reducing  overcrowding.    The  State  complains  that  the  court  ap-
proved  the  State’s  population  reduction  plan  without  considering 
whether  its  specific  measures  would  substantially  threaten  public
safety.  But the court left state officials the choice of how best to com-
ply and was not required to second-guess their exercise of discretion.
Developments  during  the  pendency  of  this  appeal,  when  the  State
has  begun  to  reduce  the  prison  population,  support  the  conclusion 
that a reduction can be accomplished without an undue negative ef-
fect on public safety.  Pp. 37–41.

2. The three-judge court’s order, subject to the State’s right to seek
its  modification  in  appropriate  circumstances,  must  be  affirmed. 
Pp. 41–48.  

(a) To comply with the PLRA, a court must set a population limit
at  the  highest  level  consistent  with  an  efficacious  remedy,  and  it
must  order  the  population  reduction  to  be  achieved  in  the  shortest 
period of time reasonably consistent with public safety.  Pp. 41–42. 

(b) The three-judge court’s conclusion that the prison population
should be capped at 137.5% of design capacity was not clearly errone-
ous.  The  court  concluded  that  the  evidence  supported  a  limit  be-
tween the 130% limit supported by expert testimony and the Federal
Bureau  of  Prisons  and  the  145%  limit  recommended  by  the  State
Corrections Independent Review Panel.  The PLRA’s narrow tailoring 
requirement  is  satisfied  so  long  as  such  equitable,  remedial  judg-