Document ID: ./input/supremecourt_opinions/opinions/23pdf/22-899_97be.pdf
Page Number: 40.0

Cite as:  602 U. S. ____ (2024) 

9 

ALITO, J., concurring in judgment 

be given upon request.  Plus, of course, an expert’s lack of 
personal knowledge of the “facts or data” that are called to 
his attention can be brought out in cross examination and 
stressed in a closing argument. 

This  modern  system  is  more  honest  because  it  reflects
how experts actually form opinions.  See Advisory Commit-
tee’s Notes on Fed. Rule Evid. 703, at 393 (describing the
Rule as “designed to . . . bring the judicial practice in line 
with  the  practice  of  the  experts  themselves  when  not  in
court”).  It  is  simpler  and  less  likely  to  confuse.    And  it 
avoids many of the pitfalls of the old procedure.  It may not 
be perfect—and evidence scholars have proposed a variety 
of reforms—but it is unquestionably better than the old re-
gime it replaced. 

II 
In light of the woeful history of expert testimony by hy-
potheticals, why has the Court disinterred that procedural
monstrosity?  The Court reasons that “[i]f an expert for the
prosecution conveys an out-of-court statement in support of 
his opinion, and the statement supports that opinion only if 
true, then the statement has been offered for the truth of 
what it asserts.”  Ante, at 14.  Or put differently, “the truth
of the basis testimony is what makes it useful to the prose-
cutor;  that  is  what  supplies  the  predicate  for—and  thus 
gives value to—the state expert’s opinion.”  Ibid.  In other 
words, the Court seems to think that all basis testimony is
necessarily offered for its truth.

This  is  just  plain  wrong.  What  makes  basis  evidence 
“useful” is the assistance it gives the fact-finder in judging 
the weight that should be given to the expert’s opinion.  See 
Advisory Committee’s Notes on Rule 703 (basis testimony 
may  be  brought  before  a  jury  to  help  it  “evaluate  the  . . . 
opinion”).  And  a  trial  judge  must,  upon  request,  instruct
the jury to consider it only for that purpose.  If a judge rules