                            PUBLISHED

UNITED STATES COURT OF APPEALS
                FOR THE FOURTH CIRCUIT


UNITED STATES OF AMERICA,              
                 Plaintiff-Appellee,
                 v.                              No. 05-5223
JAMES EDWARD ELSTON, JR.,
             Defendant-Appellant.
                                       
           Appeal from the United States District Court
         for the Western District of Virginia, at Roanoke.
                  Glen E. Conrad, District Judge.
                            (CR-05-8)

                      Argued: November 29, 2006

                       Decided: March 13, 2007

        Before WILLIAMS and KING, Circuit Judges, and
               HAMILTON, Senior Circuit Judge.



Affirmed by published opinion. Judge King wrote the opinion, in
which Judge Williams and Senior Judge Hamilton joined.


                             COUNSEL

ARGUED: Paul Graham Beers, GLENN, FELDMANN, DARBY &
GOODLATTE, Roanoke, Virginia, for Appellant. Jean Barrett Hud-
son, Assistant United States Attorney, OFFICE OF THE UNITED
STATES ATTORNEY, Charlottesville, Virginia, for Appellee. ON
BRIEF: John L. Brownlee, United States Attorney, Roanoke, Vir-
ginia, for Appellee.
2                      UNITED STATES v. ELSTON
                              OPINION

KING, Circuit Judge:

   James Edward Elston, Jr., appeals from the district court’s denial
of his motion to suppress evidence of a handgun found in his vehicle
by police officers in Roanoke, Virginia. See United States v. Elston,
No. 7:05-cr-00008 (W.D. Va. April 18, 2005) (memorandum opinion
denying defendant’s motion to suppress) (the "Opinion").1 Elston was
convicted, in the Western District of Virginia, of possession of a fire-
arm by a convicted felon (in violation of 18 U.S.C. § 922(g)), on a
conditional plea of guilty. He reserved his right of appeal on the sup-
pression issue, and contends that the handgun on which his § 922 con-
viction rests was the fruit of an unlawful search and seizure. As
explained below, we reject this contention and affirm.

                                   I.

                                   A.

   In the early morning hours of January 15, 2005, a Roanoke 911
operator received a report of a drunk driver from a woman identifying
herself as Melba Taylor. Taylor asked the operator not to disclose her
name to the police, because she was afraid that Elston, who was the
subject of her call, would learn that she had reported him; the operator
honored Taylor’s request, and did not provide her name to the officers
who responded to the 911 call. Taylor advised the operator that a
highly intoxicated driver was leaving her home in Roanoke’s Lans-
downe housing project, "driving crazy" and headed towards either a
nearby Family Dollar store or his own home in an area known as
Wellmont Farms. J.A. 111. She reported that the driver’s name was
Jimmy, and that he had recently been released from a jail sentence
imposed for assaulting the mother of his child. Taylor described the
drunk driver as a black male wearing a light blue sweater, jeans, and
white tennis shoes, and described his vehicle as a dark blue, 2003-
model pickup truck with black-tinted windows, a large silver toolbox
    1
   The Opinion of the district court is found at J.A. 132-39. (Citations
herein to "J.A. ___" refer to the contents of the Joint Appendix filed by
the parties in this appeal.)
                        UNITED STATES v. ELSTON                         3
in back, and handicapped plates bearing license number 270464. She
further advised that the driver had in his truck a loaded 9mm hand-
gun, along with three clips of ammunition, and that he had threatened
to "let[ ] them off in somebody." J.A. 109.

   Immediately after Taylor’s call, another 911 operator radioed
police officers in the area, advising them of Taylor’s report that a sub-
ject was outside the Lansdowne project with a loaded 9mm handgun
and several clips, and that he had brandished the weapon. This second
operator relayed to the officers Taylor’s description of the subject and
his vehicle. Meanwhile, the operator who had taken Taylor’s call
broadcast additional information over a computerized text-display
system available in Roanoke police patrol cars. This information
included Taylor’s assertion that the subject had threatened to "let[ ]
the gun off." J.A. 104.

  Within minutes of the 911 dispatch, Officer Jason Hicks of the
Roanoke Police located a truck matching the description provided by
Taylor, parked in a lot adjacent to the Lansdowne project. Officer
Hicks observed that the truck’s driver, later identified as defendant
Elston, was a black male wearing a blue shirt. With his service
weapon drawn, Hicks ordered Elston out of the truck and handcuffed
him. During this process, Hicks smelled a strong odor of alcohol on
Elston.

   As Officer Hicks was detaining Elston, Officer Travis Reed, who
had also responded to the 911 dispatch, examined the truck. Officer
Reed has given conflicting statements regarding the circumstances of
this examination. In a written report filed shortly after the incident, on
January 20, 2005, he said that he had first opened the truck door and
then observed a handgun grip protruding from between the driver’s
seat and the center console. On April 14, 2005, however, at Elston’s
suppression hearing in the district court, Reed testified that his written
report was incorrect, and that Elston actually had left the truck door
open when he exited the vehicle, leaving the handgun grip visible to
an observer standing outside the vehicle.

  After Officer Reed discovered the handgun inside Elston’s truck,
Officer Hicks contacted a police dispatcher and learned that Elston
was a convicted felon. Elston was then informed that he was under
4                      UNITED STATES v. ELSTON
arrest, and was taken to jail. On January 27, 2005, Elston, who had
three previous convictions for felony offenses, was charged with a
violation of 18 U.S.C. § 922(g), which prohibits a convicted felon
from possessing a firearm.

   On April 1, 2005, Elston filed a motion to suppress evidence of the
handgun found in his truck, maintaining that the officers had contra-
vened his Fourth Amendment rights both in detaining him and in
searching his vehicle. The district court conducted a hearing on Els-
ton’s suppression motion on April 14, 2005, and, four days later, on
April 18, 2005, issued its Opinion denying the motion. In so ruling,
the court concluded that Taylor’s 911 call had the same legal status
as an anonymous tip, because her identity, although known to the 911
operator, had not been relayed to the officers. See Opinion 4-5. None-
theless, the court decided that the officers’ initial stop of Elston was
reasonable, because it was based on information that bore substantial
indicia of reliability and indicated that Elston posed a serious danger
to the public. See Opinion 5-6. The court also determined that the
officers’ initial detention of Elston was only a Terry stop, rather than
a full arrest, and that the officers had not conducted an unlawful
search of Elston’s truck. See Opinion 7-8.

   On July 29, 2005, Elston entered a conditional guilty plea, contin-
gent on the outcome of his appeal of the district court’s ruling on his
suppression motion. See Fed. R. Crim. P. 11(a)(2) (authorizing condi-
tional guilty pleas). On October 28, 2005, the court sentenced Elston
to twenty-seven months’ imprisonment. Elston has timely appealed
the denial of his motion to suppress, and we possess jurisdiction pur-
suant to 28 U.S.C. § 1291.

                                   B.

   In an appeal of a district court’s ruling on a motion to suppress evi-
dence, we review the court’s legal conclusions de novo and its under-
lying factual findings for clear error. See United States v. Rusher, 966
F.2d 868, 873 (4th Cir. 1992).

                                   II.

 Elston contends that the Roanoke officers violated his Fourth
Amendment rights both in detaining him and in searching his truck.
                       UNITED STATES v. ELSTON                         5
He asserts that the 9mm handgun found in the truck was the fruit of
these unlawful acts by the officers, and that the district court thus
erred in denying his motion to suppress evidence of the firearm. In its
Opinion, the court concluded that the officers’ initial detention of Els-
ton was a temporary, investigatory stop of the kind authorized by the
Supreme Court in Terry v. Ohio, 392 U.S. 1 (1968), and that Taylor’s
911 call had given the officers a sufficient basis to conduct such a
Terry stop. Elston challenges both aspects of that ruling. First, he
maintains that, at the time they detained him, the officers did not pos-
sess information sufficient to warrant a Terry stop. See Opinion 5-7.
Second, Elston asserts that his initial detention was actually a full
arrest rather than a temporary detention under Terry, and that even if
the officers could have lawfully carried out a Terry stop, they lacked
probable cause to arrest him. Elston’s third appellate contention is
that Officer Reed conducted a warrantless search of his truck that was
not justified by any of the recognized exceptions to the Constitution’s
warrant requirement. As we will explain, none of Elston’s contentions
withstands scrutiny.

                                   A.

   Elston first asserts that the district court erred in concluding that
the officers possessed a sufficient basis to subject him to a Terry stop.
His contention in this regard depends on the proposition, accepted by
the district court, that Taylor’s 911 call was anonymous because only
the 911 operator, and not the officers, knew Taylor’s identity at the
time of the detention and search. Proceeding from that premise, Els-
ton relies on the precedent of Florida v. J.L., 529 U.S. 266 (2000),
and United States v. Brown, 401 F.3d 588 (4th Cir. 2005) — each of
which examined a report from an anonymous informant and deemed
it insufficient to justify a Terry stop — for his view that the district
court erroneously decided that the stop conducted here was reason-
able.

   J.L. involved an anonymous tip "that a young black male standing
at a particular bus stop and wearing a plaid shirt was carrying a gun."
529 U.S. at 268. The Supreme Court ruled that this "bare-boned,"
anonymous tip, standing alone, was insufficient to justify a Terry
stop. Id. at 273-74. The Court also rejected Florida’s assertion that the
tip did not need to satisfy the usual standards of reliability merely
6                       UNITED STATES v. ELSTON
because it alleged that its subject was carrying a firearm. Id. at 272-
73. In declining to adopt the so-called "firearm exception" that Florida
advocated, however, the Court observed that a report of an emergency
situation, such as a person carrying a bomb, might justify a Terry stop
even if it did not satisfy the standards of reliability that would apply
in less urgent circumstances. Id. at 273-74.

   Our 2005 decision in Brown applied the principles of J.L. to an
anonymous report that "a short, black male with glasses was carrying
a firearm outside the Roseman Court apartment complex" in Newport
News, Virginia. 401 F.3d at 590. We concluded that so spare a tip,
coming from an anonymous informant, lacked the indicia of reliabil-
ity necessary to justify a Terry stop. See id. at 596.

   The Government maintains that the district court erred in treating
Taylor’s 911 call as anonymous, and that J.L. and Brown are therefore
inapposite. We can decide this appeal without reaching that question,
however, because the information that the 911 operators provided to
the officers in the field supplied a sufficient basis for a Terry stop of
Elston — even if we assume, for purposes of our analysis, that Taylor
was an anonymous informant.2 It is well established that anonymous
information can furnish grounds for a reasonable search or seizure if
it exhibits sufficient indicia of reliability. See J.L., 529 U.S. at 270;
United States v. Perkins, 363 F.3d 317, 323 (4th Cir. 2004). Our deci-
sions provide guidance on the factors that can indicate the reliability
of anonymous information. We have recognized, for example, that an
anonymous call is more likely to be reliable if it provides substantial
detail about the individuals and the alleged criminal activity it
    2
   The district court’s conclusion that Taylor was an anonymous caller
because only the 911 operator knew her name is in tension with our deci-
sion in United States v. Quarles, 330 F.3d 650 (4th Cir. 2003), where we
expressly relied on the 911 operator’s knowledge of a caller’s identifying
details in ruling that the call was a valid basis for a Terry stop. See id.
at 655. Quarles did not squarely address, however, the issue of whether
a 911 call is anonymous when only the 911 operator knows the caller’s
identity, and so we treat that question as undecided in this Circuit. We
need not reach it today, because the information from Taylor’s call that
was relayed to the officers in the field was sufficient to support their
Terry stop of Elston.
                        UNITED STATES v. ELSTON                         7
describes; if it discloses the basis of the informant’s knowledge; and,
especially, if the informant indicates that her report is based on her
contemporaneous personal observation of the call’s subject. See
United States v. Quarles, 330 F.3d 650, 655 (4th Cir. 2003) (giving
weight to informant’s "detailed description of the defendant"); Per-
kins, 363 F.3d at 324 (distinguishing J.L. on ground that caller in Per-
kins had "revealed her general location and her basis of knowledge,
as the nature and substance of her tip made clear that she was in close
proximity to the men and that she was observing them while she was
on the phone"). Another — and even more significant — indicator
that an anonymous informant is reliable is her disclosure of informa-
tion that would enable authorities to identify her if they deem it neces-
sary to do so. See Quarles, 330 F.3d at 656 (concluding that call’s
reliability was enhanced because informant provided "enough infor-
mation for the police to track [him] down," and "enough that [he] is
bound to have felt as though he was being held accountable for what
he was saying").

   In sharp contrast to the "bare-boned" tips considered in J.L. and
Brown, Taylor’s 911 report, as communicated to the officers who
detained Elston and searched his truck, possessed all of these impor-
tant indicia of reliability. Taylor provided a wealth of detail about Els-
ton’s appearance, vehicle, weapon, behavior, and state of mind. She
volunteered that Elston had just departed the Lansdowne housing
project after uttering a threat to shoot someone, indicating that the
basis of her report was her contemporaneous personal observation of
Elston’s conduct. And, perhaps most important, by indicating that
Elston had left her presence only moments before she dialed 911,
Taylor enabled the authorities to identify her simply by finding out
who Elston had been with immediately before he was detained. As the
district court properly recognized, these facts place Taylor’s 911
report in a category far removed from the brief, general tips at issue
in J.L. and Brown.

   Of additional significance is the fact that Taylor was reporting an
imminent threat to public safety — an individual who had expressly
threatened to shoot someone in the very near future. No such emer-
gency was presented in either J.L. or Brown. Indeed, in J.L., the
Supreme Court went out of its way to distinguish the hypothetical sit-
uation in which an anonymous caller reports an urgent danger to the
8                      UNITED STATES v. ELSTON
community, acknowledging that such compelling circumstances could
render reasonable a detention that might otherwise be impermissible.
See J.L., 529 U.S. at 273-74. The imminent threat faced by these offi-
cers carries substantial weight in assessing the reasonableness of their
actions, and further distinguishes this matter from the precedents on
which Elston seeks to rely.

   In sum, Taylor’s 911 report, even if anonymous, bore strong indi-
cia of reliability and alerted the police officers to a serious and immi-
nent danger. Given such circumstances, the district court did not err
in concluding that the officers possessed information sufficient to jus-
tify a Terry stop of Elston.

                                   B.

   Elston next contends that the district court erroneously classified
his initial detention by the police as a Terry stop rather than as a full
arrest. He maintains that the court therefore erred in assessing the
detention’s lawfulness under the reasonable suspicion standard that
governs temporary stops under Terry, instead of the probable cause
test that applies to arrests. Elston offers two reasons for his assertion
in this regard. First, he points to Officer Hicks’s suppression hearing
testimony that, at the time Hicks initially detained Elston, Hicks "ef-
fectively . . . consider[ed] him under arrest," even though Hicks did
not formally arrest Elston until after learning that he was a felon in
possession of a firearm. J.A. 65. Second, Elston maintains that no rea-
sonable person in the circumstances of his initial detention would
have believed himself free to leave, and that the detention was thus
an arrest rather than a Terry stop.

   Both aspects of Elston’s position on this point misapprehend the
controlling legal principles. First, the subjective views of a police
officer who effects a detention have no bearing on whether that deten-
tion constitutes an arrest. Rather, an arrest is defined using an objec-
tive standard: whether "the suspect’s freedom of action is curtailed to
a degree associated with formal arrest." Park v. Shiflett, 250 F.3d 843,
850 (4th Cir. 2001) (internal quotation marks omitted); cf. Stansbury
v. California, 511 U.S. 318, 323 (1994) (observing that "determina-
tion of custody depends on the objective circumstances of the interro-
gation, not on the subjective views harbored by either the
                       UNITED STATES v. ELSTON                         9
interrogating officers or the person being questioned"). Accordingly,
Elston’s initial detention was not an arrest merely because Hicks
regarded him as "effectively . . . under arrest" at that time. J.A. 65.

   Similarly immaterial is Elston’s assertion that no reasonable person
would have felt free to leave in the circumstances of his initial deten-
tion. We have expressly recognized that "the perception that one is
not free to leave is insufficient to convert a Terry stop into an arrest.
A brief but complete restriction of liberty is valid under Terry."
United States v. Leshuk, 65 F.3d 1105, 1109 (4th Cir. 1995) (internal
alteration marks omitted). Additionally, we have observed that "Terry
stops differ from custodial interrogation in that they must last no lon-
ger than necessary to verify or dispel the officer’s suspicion," not
because of "the absence of any restriction of liberty." Id. Elson does
not maintain that his detention lasted longer than was necessary to
verify the officers’ suspicions that he had a handgun; indeed, the offi-
cers located Elston’s weapon almost immediately after detaining him.
That he was not free to leave during the officers’ brief period of
investigation does not transform his detention into an arrest.

   Importantly, the techniques that the officers used to effect Elston’s
detention were consistent with an investigatory stop under Terry. Our
decisions have recognized that "drawing weapons, handcuffing a sus-
pect, placing a suspect in a patrol car for questioning, or using or
threatening to use force does not necessarily elevate a lawful stop into
a custodial arrest." Leshuk, 65 F.3d at 1109-10. These officers reason-
ably suspected that Elston was armed and dangerous, and thus did not
exceed the limits of a Terry stop by drawing their weapons and plac-
ing Elston in handcuffs. In these circumstances, the district court
committed no error in concluding that Elston’s initial detention by the
officers did not rise to the level of a custodial arrest.

                                   C.

   Finally, Elston maintains that Officer Reed unlawfully searched his
truck, and that the district court thus erred in refusing to suppress the
9mm handgun that was seized from the truck in Reed’s search. The
court reached its contrary conclusion by characterizing Reed’s inves-
tigation of the truck as a protective search, authorized under Michigan
10                      UNITED STATES v. ELSTON
v. Long, 463 U.S. 1032 (1983).3 In Long, the Supreme Court ruled
that officers conducting a Terry stop may carry out a protective search
of the suspect’s vehicle if they have a reasonable belief that the sus-
pect is dangerous and may gain control of weapons inside the vehicle.
See id. at 1049-50. Such a protective search is authorized even if the
suspect is under police restraint at the time the search is conducted,
because the suspect may be able to escape such restraint, or may later
regain access to the vehicle if he is not arrested. See id. at 1051-52;
United States v. Holmes, 376 F.3d 270, 280 (4th Cir. 2004).

   Elston contends that Long is inapposite here, because Officer Hicks
testified that, even if he had not arrested Elston, he would not have
allowed Elston to drive the truck due to Elston’s intoxication. Elston’s
assertion in that regard, however, misses the point. Long’s rationale
is that a suspect who is temporarily under police restraint might none-
theless, at some later point in the encounter, have the chance to
retrieve a weapon from his vehicle. Whether the suspect would be
allowed to drive the vehicle away from the scene is immaterial to the
Long inquiry. Here, if the officers had not arrested Elston — still a
possibility during the Terry stop — he would have been released from
the officers’ physical control, creating a risk that he could retrieve his
9mm handgun from the truck. Under the standard spelled out in Long,
the officers were authorized to conduct a protective search of Elston’s
truck in conjunction with the Terry stop. Elston’s contrary contention
is therefore without merit.
  3
    As we have explained, the record contains conflicting evidence
regarding Officer Reed’s investigation of Elston’s truck. Reed’s written
report of January 20, 2005 (which, according to counsel at oral argument,
was admitted at the suppression hearing for all purposes), asserted that
Reed observed the handgun in Elston’s truck only after opening the
driver-side door. In his testimony of April 14, 2005, however, Reed
stated that Elston had left the door open after exiting the vehicle, allow-
ing Reed to observe the handgun from outside the truck. The district
court made no finding on which of Officer Reed’s accounts was the cor-
rect one, nor does the court’s reasoning clearly indicate which of the two
versions it credited. In any event, we conclude that Reed was authorized
to search Elston’s truck, and so the court’s failure to expressly resolve
this apparent conflict is irrelevant to our disposition of this appeal.
                       UNITED STATES v. ELSTON                      11
                                 III.

  For the foregoing reasons, we affirm the ruling of the district court
on the suppression motion.

                                                          AFFIRMED
