Document ID: ./input/supremecourt_opinions/opinions/10pdf/09-1233.pdf
Page Number: 43.0

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

37 

Opinion of the Court 

2 
In  reaching  its  decision,  the  three-judge  court  gave
“substantial  weight”  to  any  potential  adverse  impact  on
public safety from its order.  The court devoted nearly 10 
days  of  trial  to  the  issue  of  public  safety,  and  it  gave  the 
question  extensive  attention  in  its  opinion.   Ultimately,
the  court  concluded  that  it  would  be  possible  to  reduce 
the  prison  population  “in  a  manner  that  preserves  public 
safety  and  the  operation  of  the  criminal  justice  system.” 
Juris. App. 247a–248a. 

The  PLRA’s  requirement  that  a  court  give  “substantial
weight”  to  public  safety  does  not  require  the  court  to  cer-
tify  that  its  order  has  no  possible  adverse  impact  on  the 
public.  A contrary reading would depart from the statute’s 
text by replacing the word “substantial” with “conclusive.”
Whenever  a  court  issues  an  order  requiring  the  State  to 
adjust  its  incarceration  and  criminal  justice  policy,  there 
is a risk that the order will have some adverse impact on
public  safety  in  some  sectors.    This  is  particularly  true 
when  the  order  requires  release  of  prisoners  before  their 
sentence  has  been  served.  Persons  incarcerated  for  even 
one offense may have committed many other crimes prior 
to  arrest  and  conviction,  and  some  number  can  be  ex-
pected  to  commit  further  crimes  upon  release.  Yet  the 
PLRA  contemplates  that  courts  will  retain  authority  to 
issue orders necessary to remedy constitutional violations, 
including authority to issue population limits when neces-
sary.  See supra, at 28–29.  A court is required to consider 
the  public  safety  consequences  of  its  order  and  to  struc-
ture, and monitor, its ruling in a way that mitigates those 
consequences  while  still  achieving  an  effective  remedy  of 
the constitutional violation. 

This  inquiry  necessarily  involves  difficult  predictive 
judgments  regarding  the  likely  effects  of  court  orders.
Although  these  judgments  are  normally  made  by  state
officials,  they  necessarily  must  be  made  by  courts  when