THE STATE OF COLORADO, PETITIONER V. ANTONIO GUADALUPE NUNEZ

   No. 82-1845

   In the Supreme Court of the United States

   October Term, 1983

   On Writ of Certiorari to the Supreme Court of the State of Colorado

   Brief for the United States as Amicus Curiae supporting Petitioner

            TABLE OF CONTENTS
   Interest of the United States
   Statement
   Summary of argument
   Argument:
      Respondent's testimony did not entitle him to
      compel the disclosure of the informant's identity
   Conclusion

                          QUESTION PRESENTED

   Whether a criminal defendant seeking to suppress evidence obtained
pursuant to a facially valid warrant that was based in part on
information supplied by a confidential informant may compel the
disclosure of the informant's identity by offering his own testimony
tending to show that the informant's statements were false.

                     INTEREST OF THE UNITED STATES

   This case presents a question concerning the circumstances in which
the prosecution may be required to disclose the identity of a
confidential informant during a hearing on a motion to suppress
evidence challenging the accuracy of information contained in a search
warrant affidavit.  The use of informants is vital to the law
enforcement efforts of the United States in many areas, particularly
those dealing with organized crime and narcotics.  The premature or
unnecessary disclosure of informants' identities can subject them to
reprisals, and even the possibility that such disclosures might occur
can substantially undermine the government's ability to conduct
investigations, gather evidence, and bring prosecutions.  The United
States therefore has a substantial interest in ensuring that the
identities of confidential informants not be revealed unnecessarily.

                               STATEMENT

   On November 7, 1981, Sergeant DeNovellis of the Denver police force
executed an affidavit stating in part that a confidential informant
had told him that during the previous day the informant saw
respondent, at respondent's home, in possession of a large amount of
heroin.  The affidavit recited that the informant said he had seen
respondent diluting the heroin and packaging it in balloons, and that
respondent had told the informant that respondent had just returned
from Mexico with five ounces of heroin.  Sergeant DeNovellis'
affidavit further stated that the informant was familiar with the
appearance of heroin and had admitted using it, and that the informant
had proved reliable on at least two occasions in the previous 18
months, "giving your affiant information involving narcotic activity,
and resulting in the recovery of a quantity of heroin." J.A. 5,
135-136.

   On the basis of this affidavit, a local judge issued a search
warrant.  Police officers searched respondent's house pursuant to the
warrant.  Respondent was at home during the search and the officers
found heroin on respondent's person.  He was arrested and charged with
possession of heroin.  Before trial, respondent filed motions to
compel the disclosure of the informant's identity and to suppress the
heroin.  J.A. 136.

   At a hearing on the motions, respondent testified that he had been
on a hunting trip from October 31 until November 6 and that he had not
been to Mexico during that period, nor told anyone that he had been to
Mexico during that period.  Respondent testified that only family
members had been in his house on November 6;  he also testified that
he knew of heroin only through television and newspapers.  Sergeant
DeNovellis also testified at the suppression hearing and stood by the
statements he made in his affidavit.  J.A. 43-46, 54, 59-64.

   On the basis of this testimony, the trial court ordered the State
to disclose the identity of the confidential informant to respondent.
When the State refused to do so, the trial court ordered the heroin
suppressed.  The State appealed, and the Colorado Supreme Court
affirmed.  J.A. 134-139.  The Colorado Supreme Court explained (id. at
138-139;  footnotes and citations omitted):

         The People argue that the disclosure of confidential
      informants is limited to situations in which the veracity of the
      affiant-police officer is successfully attacked.  This
      contention misapprehends the holding of People V. Dailey, (639
      P.2d 1068 (Colo. 1982)).  Dailey recognized that errors in an
      affidavit for a search warrant can result "from the informant's
      perjury or reckless disregard for the truth, or from the
      negligence or good faith mistake of either the officer or the
      informant." 639 P.2d at 1075.  When, following a veracity
      hearing, the probability of one of those kinds of error has been
      found, the election of remedies or sanctions is left to the
      discretion of the (trial) court.  The necessary foundation for
      the court's exercise of discretion in ordering disclosure is a
      showing of a reasonable basis in fact to question the accuracy
      of the informant's recitals.

         * * * Where the (trial) court has determined that the
      defendant has shown a good faith basis in fact to question the
      accuracy of an affidavit containing recitals based on
      information supplied by an unnamed informant and consequently
      has ordered that the informant be disclosed or be produced for
      an in camera hearing, we will not disturb that ruling.

                          SUMMARY OF ARGUMENT

   The decision of the Colorado Supreme Court is inconsistent with two
important principles established by this Court-- the rule of Franks V.
Delaware, 438 U.S. 154 (1978), that a facially valid search warrant
can be challenged only if the defendant makes a substantial showing
that the affiant's statements were deliberately false or recklessly
inaccurate;  and the informant's privilege, which permits the
government to withhold the identity of a confidential informant unless
the defendant makes a compelling showing that he must learn the
informant's identity.

   1. In Franks, the Court emphasized the costs of allowing a warrant
that shows probable cause on its face to be challenged in a
suppression hearing.  Such challenges use judicial resources and give
defendants an opportunity to discover the government's case.  For
these reasons, the Court in Franks took care to hold that a defendant
is not entitled to a hearing on his challenge to a facially valid
warrant unless he makes a substantial preliminary showing that the
affiant's statements were deliberately false or recklessly inaccurate.

   The only showing respondent made was his own self-serving testimony
contradicting the informant's statements.  Since many criminal
defendants will perjure themselves in order to obstruct a prosecution,
to allow a defendant's testimony alone to compel a hearing on the
truthfulness of a search warrant affidavit is almost tantamount to
requiring such a hearing on the defendant's demand-- a course
emphatically rejected by Franks.  Moreover, respondent's testimony
tended to show only that the informant's statements were false.  Even
if credited, respondent's testimony did not tend to show-- what Franks
and basic Fourth Amendment principles require-- that the affiant's
statements were recklessly or deliberately false.

   Not only did respondent's testimony fail to satisfy Franks;  it did
not approach being sufficient to require the disclosure of the
informant's identity.  The reasons for the informant's privilege are
apparent.  The government often continues to use an informant after he
has supplied information in connection with a particular prosecution;
and, more important, an informant whose identity has been revealed can
be subject to the most serious reprisals at the hands of those he
incriminates.  Moreover, because potential informants will commonly be
extremely wary-- often with good reason-- not only actual disclosures
of informants' identities, but the threat of disclosure, or even the
perception that disclosure is a serious possibility, can have a
devastating effect on the ability of law enforcement authorities to
recruit informants.  Indeed, even in camera disclosures can have a
harmful effect.

   For these reasons, the Court has ruled that a defendant must make a
substantial showing of need in order to discover an informant's
identity even when the informant's testimony will be relevant to the
question of guilt or innocence.  When an informant's testimony will be
relevant only at a suppression hearing, the defendant's burden is much
greater.  And when the informant's testimony is sought only to impeach
a search warrant that is valid on its face, the disclosure of the
informant's identity should be permitted, if at all, only in the most
extraordinary circumstances.

   The Colorado Supreme Court allowed respondent to meet this burden
with his own self-serving testimony.  If such testimony is sufficient
to require the disclosure of the informant's identity, any defendant
who is willing to contradict the statements of an informant can defeat
a criminal prosecution entirely whenever law enforcement authorities
fear that disclosing the informant's identity will risk subjecting him
to reprisals, because most prosecutors will permit crucial evidence to
be suppressed before they will take such a risk.  An approach that
permits a defendant to escape prosecution so easily should not be
sanctioned.

   2. Even when a trial court determines that a defendant has made the
substantial preliminary showing required by Franks, it should not
order the disclosure of the informant's identity, even in camera, as a
matter of course.  The court can allow cross-examination of the
affiant by defense counsel.  In addition, the affiant can be
questioned more searchingly in camera by the court.

   Such examination of the affiant should ordinarily be sufficient to
enable the trial judge to decide if the affiant has deliberately or
recklessly made false statements.  The informant's testimony should
seldom be necessary, because the issue is the credibility of the
affiant-- who is usually a law enforcement officer-- and a trial judge
will usually be able to reach a conclusion about the officer's
truthfulness by observing his testimony.  Indeed, if the informant's
identity is being withheld because of the danger of reprisals, any
testimony the informant gives under circumstances in which he fears
that the defendant might learn his identity-- circumstances that can
include an in camera hearing-- will necessarily be suspect.

   For these reasons, requiring the testimony of the informant, even
in camera, should be the last resort.  But if the trial judge
nevertheless decides that the informant's testimony is necessary, we
can think of no reason why an in camera examination of the informant
will not always suffice.  It is true that adversary proceedings are
customary in our system, but the Fourth Amendment is an exception;
the Warrant Clause reflects a judgment that an in camera, ex parte
proceeding is adequate to protect the interests underlying that Clause
if an adversary proceeding would impose excessive costs on important
societal interests.

                               ARGUMENT

 RESPONDENT'S TESTIMONY DID NOT ENTITLE HIM TO COMPEL THE DISCLOSURE
OF THE INFORMANT'S IDENTITY

   A. The decision of the Colorado Supreme Court is inconsistent with
this Court's decisions in two distinct and important ways.  /1/ First,
the Colorado Supreme Court did not heed the rule of Franks V.
Delaware, 438 U.S. 154 (1978), that a challenge to a facially valid
search warrant will be permitted only if the defendant makes a
substantial showing that the affidavit supporting the warrant contains
material statements that were intentionally false or made with
reckless disregard of the truth.  Second, the Colorado Supreme Court
gave grossly insufficient weight to the so-called informant's
privilege-- the government's right to withhold the identity of an
informant unless the defendant can show a compelling need for
disclosure.

   1. The Colorado Supreme Court did not suggest that Sergeant
DeNovellis's affidavit, on its face, failed to establish probable
cause, and the affidavit manifestly does show probable cause if its
statements are accepted as true.  In Franks, this Court held that
evidence obtained pursuant to a warrant based on such an affidavit may
not be suppressed unless the defendant shows that the affidavit
contained material statements that were intentionally false, or were
made with reckless disregard of the truth.  Innocent or negligent
inaccuracies, the Court held, do not taint the warrant or require
suppression of the evidence.  438 U.S. at 155-156, 171.

   The Court in Franks explicitly noted that "(t)he deliberate falsity
or reckless disregard whose impeachment is permitted today is only
that of the affiant, not of any nongovernmental informant" (438 U.S.
at 171).  This follows directly from the language of the Fourth
Amendment, the decisions of this Court, and the rule of Franks itself.
 The Fourth Amendment prohibits only unreasonable searches, and "a
warrant based on information which the affiant and the magistrate both
had reasonable grounds for believing is a reasonable one" (Kipperman,
Inaccurate Search Warrant Affidavits as a Ground for Suppressing
Evidence, 84 Harv. L. Rev. 825, 832 (1971)), even if the information
is later discovered to be false or erroneous.  Warrants may issue on
probable cause, and if there was probable cause to believe the
informant's statement to be true, its falsity does not vitiate the
warrant.  The Court made this point clear many times before Franks.
See, e.g., United States V. Harris, 403 U.S. 573, 579-580 (1971)
(plurality opinion);  Rugendorf V. United States, 376 U.S. 528, 533
(1964);  Jones V. United States, 362 U.S. 257, 269-272 (1960).  See
also Brinegar V. United States, 338 U.S. 160, 176 (1949).  And of
course under Franks, if the affiant reasonably believed the
informant's false statements-- or even if he was merely negligent in
failing to discover their falsehood-- the warrant is not invalid.  The
Colorado Supreme Court gave no indication of understanding these
fundamental principles.

   Moreover, the Court in Franks emphasized that a defendant is not
entitled to a hearing on the truthfulness of a warrant affidavit as a
matter of course.  A defendant is to receive such a hearing only if he
"makes a substantial preliminary showing that a false statement
knowingly and intentionally, or with reckless disregard for the truth,
was included by the affiant in the warrant affidavit, and if the
allegedly false statement is necessary to the finding of probable
cause" (438 U.S. at 155-156).

   The Court required such a showing in large part because it was
concerned that routine inquiries into the truthfulness of statements
made in search warrant affidavits would prove burdensome and
time-consuming for the courts and would be used for discovery by
defendants.  The Court recognized that law enforcement authorities
were legitimately concerned that "if such hearings were conducted
routinely * * * they would be misused by defendants as a convenient
source of discovery.  Defendants might even use the hearings in an
attempt to force revelation of the identity of informants." 438 U.S.
at 167.  And the Court explained that "(t)he requirement of a
substantial preliminary showing" is intended "to prevent the misuse of
a veracity hearing for the purposes of discovery and obstruction" (id.
at 170).

   2. The informant's privilege serves many interests that are
distinct from, but certainly no less important than, those protected
by the rule of Franks V. Delaware:

         What is usually referred to as the informer's privilege is in
      reality the Government's privilege to withhold from disclosure
      the identity of persons who furnish information of violations of
      law to officers charged with enforcement of that law.  * * * The
      purpose of the privilege is the furtherance and protection of
      the public interest in effective law enforcement.  The privilege
      recognizes the obligation of citizens to communicate their
      knowledge of the commission of crimes to law-enforcement
      officials and, by preserving their anonymity, encourages them to
      perform that obligation.

   Roviaro V. United States, 353 U.S. 53, 59 (1957).  For these
reasons, "public policy forbids disclosure of an informer's identity
unless essential to the defense" (Scher V. United States, 305 U.S.
251, 254 (1938)).  A defendant seeking disclosure of an informant's
identity accordingly bears a substantial burden even if the
informant's testimony would be directly relevant to the question of
guilt or innocence.  See Roviaro V. United States, 353 U.S. at 60-63.
See also In re Quarles & Butler, 158 U.S. 532, 535-536 (1895) ("It is
the right, as well as the duty, of every citizen * * * to communicate
to the executive officers any information which he has of the
commission of an offence against th(e) laws;  and such information,
given by a private citizen, is a privileged and confidential
communication * * * the disclosure of which cannot be compelled
without the assent of the government.").

   The reasons for this privilege are familiar.  "'Courts have
countenanced the use of informers from time immemorial'" (Hoffa V.
United States 385 U.S. 293, 311 (1966), quoting United States V.
Dennis, 183 F.2d 201, 224 (2d Cir. 1950) (L. Hand, J.)), and the
detection and prosecution of many crimes would simply be impossible
without informants.  This Court has repeatedly upheld the use of
confidential informants as sources of information on which search
warrants are based.  See, e.g., Illinois V. Gates, No. 81-430 (June 8,
1983), slip op. 22-23;  Rugendorf V. United States, 376 U.S. at 533.
If an informant's identity is disclosed, not only is he likely to
become useless in further investigations, but he may be subject to
reprisals.  See McCray V. Illinois, 386 U.S. 300, 308-309 (1967),
quoting 8 Wigmore, Evidence Section 2374 (McNaughton rev. ed. 1961):

      Whether an informer is motivated by good citizenship, promise of
      leniency or prospect of pecuniary reward, he will usually
      condition his cooperation on an assurance of anonymity-- to
      protect himself and his family from harm (and) to preclude
      adverse social reactions * * *.  The government also has an
      interest in nondisclosure of the identity of its informers.  Law
      enforcement officers often depend upon professional informers to
      furnish them with a flow of information about criminal
      activities.  Revelation of the dual role played by such persons
      ends their usefulness to the government and discourages others
      from entering into a like relationship.

   In this area, as with most privileges, certainty and predictability
are vital.  It is not enough that most informants' identities are not
disclosed most of the time;  law enforcement officers attempting to
recruit informants must be able to assure them in advance that their
identities will not be disclosed prematurely.  "An uncertain
privilege, or one which * * * results in widely varying applications
by the courts, is little better than no privilege at all." Upjohn Co.
V. United States, 449 U.S. 383, 393 (1981).  Nowhere is this more
likely to be true than in the difficult and volatile relationship
between police and informants.  The stakes for informants can be
exceedingly high, and the informant's reaction may well be governed by
rumor and rational or irrational fears.  For this reason, in an area
in which the authorities must rely on informants, even an occasional
disclosure or the threat of disclosure can prove devastating to law
enforcement efforts.

   Even in camera disclosures can create serious difficulties.  We
assume that the inadvertent release of material revealed in camera can
be reduced to a minimum or even eliminated;  but an informant may not
understand that disclosure of his identity to a judge is innocuous.
Cf. Baldridge V. Shapiro, 455 U.S. 345, 361 (1982).  In addition, if
the informant is called to appear before a judge, there is a danger
that the fact of his appearance will become known.  Thus, while in
camera disclosure of an informant's identity is, of course, vastly
less harmful to the government's interests than public disclosure, it
is not without potential costs.

   3. Consequently, when a criminal defendant seeks to learn an
informant's identity as part of a challenge to a facially valid search
warrant, his burden is quite properly a great one.  On the defendant's
side, "the interests at stake in a suppression hearing are of a lesser
magnitude than those in the criminal trial itself" (United States V.
Raddatz, 447 U.S. 667, 679 (1980));  the defendant's interest is not
in obtaining a fair trial of his guilt or innocence but only in
furthering the prophylactic purposes of the exclusionary rule.  See
also Lego V. Twomey, 404 U.S. 477, 488-489(1972).

   Moreover, the justification for compelling the disclosure of an
informant's identity is at its weakest when the informant's tip was
used not to support a warrantless search but to obtain a warrant.  /2/
This is true because two aspects of the warrant process act as
important safeguards against falsification by the police.  First, the
warrant affidavit commits law enforcement officers beforehand to a
particular version of the facts that support the search.  This greatly
reduces the likelihood that the officers are inventing facts, because
they cannot embellish their justification for the search by drawing on
facts they learned only by conducting the search-- as they might in
the case of a warrantless search.  Here, for example, Sergeant
DeNovellis's statement that he received information that respondent
possessed balloons filled with heroin is highly credible because it
was on record before police officers found respondent with heroin
packaged in precisely that form (see J.A. 69).

   Second, when an officer's report of an informant's tip has been
included in a warrant affidavit, it has already undergone a degree--
potentially a substantial degree-- of judicial examination at the
hands of the magistrate.  In issuing the warrant, the magistrate has
necessarily reached a judgment about the affiant's credibility.  In
addition, under the Federal Rules of Criminal Procedure, the judicial
officer issuing a search warrant may insist that the affiant appear
before him and may examine the affiant and any other witnesses--
including informants-- under oath.  Fed. R. Crim. P. 41(c)(1).

   A defendant's interest in learning an informant's identity is
accordingly at its most limited when the defendant seeks only to
suppress evidence obtained under a facially valid search warrant.
Arrayed against the defendant's limited interest are both the
important policies that militate against collateral attacks on search
warrants and the government's interest in protecting the identity of
informants.  For these reasons, the Court in Franks explicitly left
open "the difficult question whether a reviewing court must ever
require the revelation of the identity of an informant (even if) a
substantial preliminary showing of falsity has been made." 438 U.S. at
170 (emphasis added).

   B. Although it is difficult to describe in the abstract the kind of
showing that should entitle a defendant to a hearing under Franks, it
seems entirely clear that respondent's showing did not approach that
necessary to obtain such a hearing-- much less to compel disclosure of
the informant's identity.  Respondent offered only his own testimony;
/3/ and that testimony purported to show only that the informant's
statements were false-- not, as this Court specifically required in
Franks, that the affiant deliberately or recklessly made a false
statement.

   1. The Court in Franks emphasized that a defendant's mere assertion
that an affidavit contained deliberate or reckless falsehoods, or his
mere demand for a hearing on the veracity of the affidavit, is
insufficient to require a hearing.  See 438 U.S. at 171.  The only
evidence respondent offered was his own testimony.  While sworn
testimony by a criminal defendant is more than a mere demand, it is
not much more.  It is hardly a controversial proposition that
defendants faced with serious criminal charges are often willing to
commit perjury in an effort to escape conviction.  Respondent, for
example, testified that he had no personal acquaintance with heroin,
even though a police officer testified that he removed heroin from
respondent's pocket (J.A. 54, 69).  To the extent a defendant's own
testimony is sufficient to entitle him to a hearing challenging a
facially valid warrant, defendants will easily and routinely
circumvent the threshold requirement for a hearing that the Court
carefully established in Franks.  See 438 U.S. at 155-156, 167, 170,
171-172.

   To be sure, it is possible to imagine instances in which a
defendant's testimony alone might be enough to require a further
hearing, under Franks, to determine whether the warrant is based on
reckless or intentional falsehoods.  This might happen, for example,
if the inherent plausibility of the defendant's statement is
particularly compelling, if the nature of the dispute makes it
impossible for the defendant to develop corroborating evidence, and if
the affiant's testimony is not credible.  But such circumstances
should be very rare, and none of these circumstances was found to be
present here.

   2. Moreover, even if respondent's testimony were accepted as true,
it was manifestly insufficient to obtain a hearing under Franks.
Respondent testified to the effect that the informant's statements
were false.  This testimony does not tend to show that the affiant's
statements were recklessly inaccurate or deliberately false;  it is at
least equally possible that Sergeant DeNovellis was innocently or
negligently misled by a deceitful or mistaken informant.  As the Court
emphasized in Franks:  "There must be allegations of deliberate
falsehood or of reckless disregard for the truth, and those
allegations must be accompanied by an offer of proof.  * * *
Allegations of negligence or innocent mistake are insufficient." 438
U.S. at 171.  Neither the trial court nor the Colorado Supreme Court
found, or suggested any basis for finding, that respondent's testimony
was a "substantial preliminary showing" (id. at 155) of reckless or
deliberate falsehood by the affiant.  Indeed, the Colorado Supreme
Court was explicit in stating that such a showing is not required.

   3. Perhaps more important, the Colorado Supreme Court held that
respondent's own testimony contradicting the informant was sufficient
not only to permit a challenge to the warrant but to require the
disclosure of the informant's identity.  When the State was unwilling
to reveal the informant's name because it feared that doing so would
place him in jeopardy (see J.A. 83), the heroin found on respondent's
person was suppressed.  In McCray V. Illinois, the Court held that a
defendant's mere demand does not entitle him to obtain the identity of
an informant at a suppression hearing.  Here, the Colorado Supreme
Court, while not ordering the disclosure of the informant's identity
on the basis of a mere demand, required such disclosure on the basis
of the defendant's testimony that the informant's tip was incorrect--
and as we have said, that amounts to little more than a mere demand.
/4/

   As this case illustrates, the Colorado Supreme Court's approach
gives any defendant who is willing to contradict an informant's
statement an easy means of defeating a criminal prosecution entirely
whenever the State will not reveal the informant's identity because it
believes it would endanger him if it did so.  This will occur even
though the statements in the search warrant affidavit were entirely
true.  Such an approach cannot be correct.  As this Court has said
(McCray V. Illinois, 386 U.S. at 306, quoting State V. Burnett, 42
N.J. 377, 385, 201 A.2d 39, 43 (1964)):

         If a defendant may insist upon disclosure of the informant in
      order to test the truth of the officer's statement that there is
      an informant or as to what the informant related or as to the
      informant's reliability, we can be sure that every defendant
      will demand disclosure.  He has nothing to lose and the prize
      may be the suppression of damaging evidence if the State cannot
      afford to reveal its source, as is so often the case.

   C. Even if a trial court determines that a defendant made the
showing required by Franks, it should not order the disclosure of an
informant's identity, even in camera, as a matter of course.  /5/ We
have previously explained that the defendant's interest in learning
the identity of an informant in order to seek the suppression of
evidence obtained through a warrant is decidedly limited, while the
government's interest in protecting the confidentiality of
informants-- even from in camera disclosures-- is substantial.  In
addition, as we will show, revealing the informant's identity will
often be less useful than it might appear in determining whether the
warrant is tainted by deliberate or reckless falsehoods;  and there
are alternative methods not requiring the disclosure of the
informant's identity for making that determination.  For these
reasons, even in camera disclosure should be the last resort.
Disclosure of the informant's identity to the defendant is warranted,
if at all, only in the most extraordinary circumstances.

   1. The issue at a hearing conducted pursuant to Franks is the
affiant's credibility, not the informant's.  The affiant will usually
be a law enforcement officer, and ultimately the trial judge will have
to decide whether he is truthful.  The judge's resolution of that
question is likely to depend principally on his assessment of the
officer's own testimony, not on the testimony of an alleged informant
whose interests and motivations may well be inscrutable.  In
particular, if an informant's identity is being kept confidential
because, according to the authorities, he fears reprisals, then any
testimony he gives after the possibility has arisen that his identity
will become known to the defendant will automatically be suspect.

   The affiant can be cross-examined by defense counsel.  The scope of
that examination will necessarily be limited by the need to protect
the informant's identity, but it can nonetheless often be very
thorough.  See, e.g., McCray V. Illinois, 386 U.S. at 303 (on
cross-examination, affiant gave names of persons convicted of
narcotics violations as a result of information supplied by
confidential informant).  Plainly the trial judge should have the
discretion to decide that cross-examination of this form is sufficient
to test the officer's credibility, and the judge should not permit
measures more likely to disclose an informant's identity unless he
specifically finds this more cautious approach to be inadequate.  Cf.
United States V. Kiser, No. 82-1487 (9th Cir. Sept. 26, 1983), slip
op. 4720 nn. 4-5 (rejecting district court's decision to proceed in
this fashion without explaining why it was inadequate, even though
suspected informant was already dead by time of suppression hearing).

   2. In addition, or alternatively, the trial judge can order an in
camera proceeding in which the affiant is questioned by the judge.
With defense counsel excluded, the affiant is likely to be able to
reveal more information, since the government need not be concerned
that the defendant will put together pieces of innocuous information
and identify the informant.  The court can, therefore, examine the
affiant more completely without requiring him to produce the informant
or even to reveal the informant's identity.  While defense counsel
would not be physically present at such a hearing, he can participate
by suggesting lines of inquiry to the trial judge.  Moreover, the
record of an in camera hearing can be reviewed by an appellate court
to determine whether the trial judge was sufficiently probing in his
inquiry.

   3. As a practical matter, a trial judge should generally be able to
assess an officer's credibility by permitting limited
cross-examination and by examining the officer in camera.  But if it
is necessary for the government to produce the informant, we can think
of no reason why an in camera examination of the informant will not
always be sufficient.  See 1 LaFave, Search and Seizure 584 (1978).

   While adversary proceedings are customary in our system, the Fourth
Amendment provides a conspicuous exception.  It reflects a judgment by
the Framers that in a wide range of cases-- at least all those in
which no adequate retrospective remedy is available-- ex parte
proceedings are sufficient to protect the interests underlying the
Warrant Clause.  Ex parte, in camera proceedings are an acceptable
basis for issuing a warrant precisely because an adversary hearing at
that stage might impair law enforcement interests.  See generally
Zurcher V. Stanford Daily, 436 U.S. 547, 560-561 (1978).  When an
adversary hearing on a motion to suppress will cause an informant's
identity to be disclosed, such a hearing will also inflict serious
costs on important societal interests.  In such instances, the ex
parte, in camera procedures that the Framers thought sufficient before
the fact should also be sufficient after the fact.  Cf. Palermo V.
United States, 360 U.S. 343, 354-356 (1959).

   Indeed, an in camera hearing to determine if evidence should be
suppressed has several advantages over a hearing before a magistrate
on a warrant application.  It will not be conducted in haste.  The
trial judge, unlike the magistrate, will be "acquaint(ed) with the
information that may contradict the good faith and reasonable basis of
the affiant's allegations" (Franks, 438 U.S. at 169).  And a trial
judge may be more inclined than a magistrate to examine the
government's evidence critically.

                              CONCLUSION

   The judgment of the Colorado Supreme Court should be reversed.

   Respectfully submitted.

   REX E. LEE

      Solicitor General

   STEPHEN S. TROTT

      Assistant Attorney General

   ANDREW L. FREY

      Deputy Solicitor General

   DAVID A. STRAUSS

      Assistant to the Solicitor General

   DECEMBER 1983

   /1/ In his Brief in Opposition, respondent contended that the
Colorado Supreme Court's decision had an adequate and independent
basis in state law (Br. in Opp. 2-3).  We take no position on this
contention but assume, throughout this brief, that the decision below
is based on federal law.

   /2/ Even the dissenters in McCray V. Illinois, supra-- a case
involving a warrantless arrest based on an informant's tip--
recognized this point.  See 386 U.S. at 314-315 (Douglas, J.,
dissenting).

   /3/ It appears from the transcript of the hearing on the
suppression motion that respondent may have offered to provide
affidavits from family members that would support his testimony (see
J.A. 56).  But the Colorado Supreme Court does not seem to have relied
on this offer in concluding that respondent had made a sufficient
showing to justify the trial court's order (see J.A. 137, 138-139).

   /4/ In addition, as we noted, the justification for requiring the
disclosure of an informant's identity is significantly weaker when a
defendant is challenging a search warrant than when he is challenging
a warrantless search like that involved in McCray.  See pages 13-14,
supra.

   /5/ There appears to be some tendency among courts to require the
in camera disclosure of an informant's identity as a matter of course
once anything approaching the preliminary showing required by Franks
has been made.  See, e.g., United States V. Kiser, No. 82-1487 (9th
Cir. Sept. 26, 1983).