Document ID: ./input/supremecourt_opinions/opinions/boundvolumes/558bv.pdf
Page Number: 186.0

Cite as: 558 U. S. 15 (2009) 

25 

Per Curiam 

to  “emotional  instability,  impulsivity,  and  impairment  of  the 
neurophysiological mechanisms for planning and reasoning.” 
Amended  Pet.  for  Writ  of  Habeas  Corpus  in  No.  CIVS– 
89–0736–EJG–JFM  (ED  Cal.),  p.  120.  But  the  cold,  calcu­
lated  nature  of  the  Howard  murder  and  Belmontes’  subse­
quent  bragging  about  it  would  have  served  as  a  powerful 
counterpoint. 

The type of “more-evidence-is-better” approach advocated 
by Belmontes and  the Court of Appeals  might seem appeal­
ing—after  all,  what  is  there  to  lose?  But  here  there  was  a 
lot  to  lose.  A  heavyhanded  case  to  portray  Belmontes  in  a 
positive  light,  with  or  without  experts,  would  have  invited 
the  strongest  possible  evidence  in  rebuttal—the  evidence 
that Belmontes was responsible for not one but two murders. 
Belmontes  counters  that  some  of  the  potential  mitigating 
evidence might not have opened the door to the prior murder 
evidence.  The  Court  of  Appeals  went  so  far  as  to  state, 
without citation, that “[t]here would be no basis for suggest­
ing that [expert testimony] would be any different if the ex­
pert were informed that Belmontes committed two murders 
rather  than  one.”  529  F.  3d,  at  869,  n.  20.  But  it  is  surely 
pertinent  in  assessing  expert  testimony  “explain[ing]  .  .  . 
involvement  in  criminal  activity,”  id.,  at  853,  to  know  what 
criminal  activity  was  at  issue.  And  even  if  the  number  of 
murders  were  as  irrelevant  as  the  Ninth  Circuit  asserted, 
the fact that  these two murders were so  different in charac­
ter made each of them highly pertinent in evaluating expert 
testimony of the sort envisioned by the Court of Appeals. 

The  Ninth  Circuit  noted  that  the  trial  court  retained  dis­
cretion  to  exclude  the  Howard  evidence  even  if  Schick 
opened  the  door.  Id.,  at  869–870,  n.  20.  If  Schick  had 
doubts,  the  Court  of  Appeals  contended,  he  could  have  se­
cured  an  answer  in  advance  through  a  motion  in  limine. 
Ibid.  The  trial  judge,  however,  left  little  doubt  where  he 
stood.  While  ruling  that  the  prosecution  could  not  present 
the evidence in its case in chief, Record 2254, the judge made