                  Cite as: 577 U. S. ____ (2015)             1

                            Per Curiam

SUPREME COURT OF THE UNITED STATES
    MARYLAND, PETITIONER v. JAMES KULBICKI
  ON PETITION FOR WRIT OF CERTIORARI TO THE COURT OF 

                APPEALS OF MARYLAND

              No. 14–848.   Decided October 5, 2015


   PER CURIAM.
   A criminal defendant “shall enjoy the right . . . to have
the Assistance of Counsel for his defence.” U. S. Const.,
Amdt. 6. We have held that this right requires effective
counsel in both state and federal prosecutions, even if the
defendant is unable to afford counsel. Gideon v. Wain-
wright, 372 U. S. 335, 344 (1963). Counsel is unconstitu-
tionally ineffective if his performance is both deficient,
meaning his errors are “so serious” that he no longer
functions as “counsel,” and prejudicial, meaning his errors
deprive the defendant of a fair trial. Strickland v. Wash-
ington, 466 U. S. 668, 687 (1984). Applying this standard
in name only, the Court of Appeals of Maryland held that
James Kulbicki’s defense attorneys were unconstitution-
ally ineffective. We summarily reverse.
   In 1993, Kulbicki shot his 22-year-old mistress in the
head at pointblank range. The two had been ensnarled in
a paternity suit, and the killing occurred the weekend
before a scheduled hearing about unpaid child support. At
Kulbicki’s trial, commencing in 1995, Agent Ernest Peele
of the FBI testified as the State’s expert on Comparative
Bullet Lead Analysis, or CBLA. In testimony of the sort
CBLA experts had provided for decades, Peele testified
that the composition of elements in the molten lead of a
bullet fragment found in Kulbicki’s truck matched the
composition of lead in a bullet fragment removed from the
victim’s brain; a similarity of the sort one would “ ‘expect’ ”
if “ ‘examining two pieces of the same bullet.’ ” 440 Md. 33,
41, 99 A. 3d 730, 735 (2014). He further testified that a
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                         Per Curiam

bullet taken from Kulbicki’s gun was not an “exac[t]”
match to the bullet fragments, but was similar enough
that the two bullets likely came from the same package.
Id., at 42–44, 99 A. 3d, at 735–736. After considering this
ballistics evidence, additional physical evidence from Kul-
bicki’s truck, and witness testimony, the jury convicted Kul-
bicki of first-degree murder.
   Kulbicki then filed a petition for postconviction relief,
which lingered in state court until 2006 when Kulbicki
added a claim that his defense attorneys were ineffective
for failing to question the legitimacy of CBLA. By then, 11
years after his conviction, CBLA had fallen out of favor.
Indeed, Kulbicki supplemented his petition once more in
2006 after the Court of Appeals of Maryland held for the
first time that CBLA evidence was not generally accepted
by the scientific community and was therefore inadmissi-
ble. See Clemons v. State, 392 Md. 339, 371, 896 A. 2d
1059, 1078 (2006).
   Kulbicki lost in the lower state courts and appealed to
the Court of Appeals of Maryland. At that point, Kulbicki
abandoned his claim of ineffective assistance with respect
to the CBLA evidence, but the high court vacated
Kulbicki’s conviction on that ground alone. Kulbicki’s coun-
sel, according to the court, should have found a report
coauthored by Agent Peele in 1991 that “presaged the
flaws in CBLA evidence.” 440 Md., at 40, 99 A. 3d, at 734.
One of the many findings of the report was that the com-
position of lead in some bullets was the same as that of
lead in other bullets packaged many months later in a
separate box. Rather than conduct “further research to
explain the existence of overlapping compositions,” the
authors “speculated” that coincidence (or, in one case, the
likelihood that separately packaged bullets originated
from the same source of lead) caused the overlap. Id., at
49, 99 A. 3d, at 739. The Court of Appeals opined that this
lone finding should have caused the report’s authors to
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                          Per Curiam

doubt “that bullets produced from different sources of lead
would have a unique chemical composition,” the faulty
assumption that ultimately led the court to reject CBLA
evidence 15 years later. Ibid.; see Clemons, supra, 369–
370, 896 A. 2d, at 1077. The authors’ “failure to fully
explore the variance,” the Court of Appeals concluded, was
“at odds with the scientific method.” 440 Md., at 50, 99
A. 3d, at 740.
   In the Court of Appeals’ view, any good attorney should
have spotted this methodological flaw. The court held that
counsel’s failure to unearth the report, to identify one of
its findings as “at odds with the scientific method,” and to
use this methodological flaw to cast doubt on CBLA during
counsel’s cross-examination of Peele, “fell short of prevail-
ing professional norms.” Id., at 50–53, 99 A. 3d, at 740–
742. Concluding that counsel’s supposed deficiency was
prejudicial, the court set aside the conviction and ordered
a new trial. Id., at 56, 99 A. 3d, at 743–744.
   We reverse. The Court of Appeals offered no support for
its conclusion that Kulbicki’s defense attorneys were
constitutionally required to predict the demise of CBLA.
Instead, the court indulged in the “natural tendency to
speculate as to whether a different trial strategy might
have been more successful.” Lockhart v. Fretwell, 506
U. S. 364, 372 (1993). To combat this tendency, we have
“adopted the rule of contemporary assessment of counsel’s
conduct.” Ibid. Had the Court of Appeals heeded this
rule, it would have “judge[d] the reasonableness of coun-
sel’s challenged conduct . . . viewed as of the time of coun-
sel’s conduct.” Strickland, supra, at 690.
   At the time of Kulbicki’s trial in 1995, the validity of
CBLA was widely accepted, and courts regularly admitted
CBLA evidence until 2003. See United States v. Higgs,
663 F. 3d 726, 738 (CA4 2011). As the Court of Appeals
acknowledged, even the 1991 report itself did not question
the validity of CBLA, concluding that it was a valid and
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                         Per Curiam

useful forensic tool to match suspect to victim. 440 Md., at
51, n. 11, 99 A. 3d, at 740, n. 11. Counsel did not perform
deficiently by dedicating their time and focus to elements
of the defense that did not involve poking methodological
holes in a then-uncontroversial mode of ballistics analysis.
   That is especially the case here, since there is no reason
to believe that a diligent search would even have discov-
ered the supposedly crucial report. The Court of Appeals
offered a single citation in support of its sweeping state-
ment that the report “was available” to Kulbicki’s counsel
in 1995—a Government Printing Office Web page accessed
by the Court of Appeals, apparently conducting its own
Internet research nearly two decades after the trial. Id.,
at 51, and n. 12, 99 A. 3d, at 741, and n. 12; see also Brief
in Opposition 14. The Web page indicates that a compila-
tion of forensic studies that included the report was “dis-
tributed to various public libraries in 1994.” 440 Md., at
51, n. 12, 99 A. 3d, at 741, n. 12. But which ones? And in
an era of card catalogues, not a worldwide web, what
efforts would counsel have had to expend to find the com-
pilation? And had they found it, would counsel really have
combed through the entire compilation, and have identi-
fied the one (of many) findings in one of the reports, the
disregard of which counsel would have recognized to be “at
odds with the scientific method”? And then, would effec-
tive counsel really have brought to the attention of the
jury a report whose conclusion was that CBLA was a valid
investigative technique in cases just like Kulbicki’s?
Neither the Court of Appeals nor Kulbicki has answers.
Given the uncontroversial nature of CBLA at the time of
Kulbicki’s trial, the effect of the judgment below is to
demand that lawyers go “looking for a needle in a hay-
stack,” even when they have “reason to doubt there is any
needle there.” Rompilla v. Beard, 545 U. S. 374, 389
(2005). The Court of Appeals demanded something close
to “perfect advocacy”—far more than the “reasonable
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                           Per Curiam

competence” the right to counsel guarantees. Yarborough
v. Gentry, 540 U. S. 1, 8 (2003) (per curiam).
   Kulbicki’s trial counsel did not provide deficient perfor-
mance when they failed to uncover the 1991 report and
to use the report’s so-called methodological flaw against
Peele on cross-examination. (We need not, and so do not,
decide whether the supposed error prejudiced Kulbicki.)
The petition for writ of certiorari is granted, and the
judgment of the Court of Appeals for Maryland is
reversed.
                                             It is so ordered.
