In the
 United States Court of Appeals
               For the Seventh Circuit
                          ____________

No. 05-2940
CLIFTON THURMAN,
                                               Plaintiff-Appellant,
                                 v.

VILLAGE OF HOMEWOOD, HARRY BOEREMA,
CURT WIEST, et al.,
                                 Defendants-Appellees.
                    ____________
            Appeal from the United States District Court
       for the Northern District of Illinois, Eastern Division.
             No. 03 CV 8950—James B. Moran, Judge.
                          ____________
     ARGUED JANUARY 17, 2006—DECIDED MAY 2, 2006
                    ____________


  Before BAUER, ROVNER, and SYKES, Circuit Judges.
  ROVNER, Circuit Judge. This case arises out of an
incident at a Home Depot in Homewood, Illinois, in which
police officers questioned the plaintiff, Clifton Thurman,
because he was in possession of a gun in the store.
Thurman contends that the questioning and detention by
the officers deprived him of his freedom of movement in
violation of his Fourth Amendment rights and that the
Village of Homewood caused the violation of his rights
by failing to properly train the officers. He further asserts
that the police officers and an attorney acting on their
behalf retaliated against him in violation of 42 U.S.C.
§ 1983 by filing a complaint against him with the Chicago
2                                                No. 05-2940

Police Department, and defamed him in violation of Illi-
nois law. Thurman’s lawsuit named the officers, the attor-
ney, and the Village of Homewood as defendants. The
district court granted summary judgment in favor of the
defendants on the federal claims, and dismissed the
state law claim for lack of jurisdiction. Accordingly, we
construe all facts along with reasonable inferences in the
light most favorable to Thurman. Fisher v. Lovejoy, 

, 661 (7th Cir. 2005).
   Thurman was shopping at Home Depot when store
employees noticed that he was armed and reported it to the
Homewood police. Thurman was dressed in jeans and a
sweatshirt, and his clothes did not signal that he was
a police officer. Officers of the Homewood Police Depart-
ment, Robert Misner and Harry Boerema, who are defen-
dants in this action, responded to that call (officers Curt
Wiest and Kenneth Strunk subsequently responded as
backup.) After speaking with the store’s assistant manager,
the officers approached Thurman and asked if he
was armed. Thurman responded in the affirmative, and
stated that he had a “star around [his] neck and credentials
in [his] pocket.” He then showed the officers his badge,
which stated Chicago Police but did not contain any
identifying information such as his name or photo.
Thurman acknowledged that badges can be stolen, and in
fact the fraudulent use of badges has been the subject
of media reports as well. See Main, Frank and Warmbir,
Steve, “Bogus badges: crooks new weapon of choice: From
the trivial to the terrible, crimes committed by cop
wannabes have exploded in the Chicago area in recent
years, an investigation shows”, Chi. Sun-Times, p. A16,
January 8, 2006 (noting that its investigation revealed that
it is easy to obtain a badge and official-looking credentials,
including purchasing real badges online). The officers
requested additional identification from Thurman, and he
produced his driver’s license and firearm registration card.
No. 05-2940                                                 3

The firearm serial number on the firearm card was whited
out and another number was hand-written in its place.
Thurman also proffered an identification card that stated
Chicago Police Department. The card contained Thurman’s
photo, but did not indicate that he was a police officer with
the department, as opposed to an employee in another
capacity. The officers then asked him for his commission
card, which is a card issued by police departments that is
signed by the police and fire commission and identifies the
person as a police officer. Thurman stated that he did not
know what a commission card was, to which one of the
officers responded that he would know what a commission
card was if he was a police officer. Commission cards are
issued to Homewood officers, but are apparently not used by
the Chicago Police Department.
  The officers also asked Thurman for the name of his
supervisor and the police district to which he was assigned.
When he indicated that he worked for the 21st District, the
officers contacted the Illinois State Police District 21 which
replied that he was not employed there.
   One of the officers who had formerly been employed
with the Chicago Housing Authority and had been famil-
iar with the 21st District area, asked Thurman to con-
firm that there were public housing buildings near the 21st
District station. Thurman responded that there was nothing
behind the police station. The officer then accused Thurman
of lying, stating that he was not actually a police officer.
  At that point, the officers, as Thurman put it, “got around
to asking” him for the phone number to the 21st District.
Thurman then provided it, and the officers promptly called
the number to verify that he was an officer there. Upon
receiving that verification, they returned the weapon to
Thurman and left the store. The entire incident took
approximately 20-25 minutes from the initial confrontation
to the resolution by Thurman’s estimate, or less than 14
4                                                No. 05-2940

minutes according to the police dispatch records from their
arrival at the scene to their departure.
  Thurman concedes that the officers properly confronted
him given the report that he was armed in the store, and
that it was appropriate for them to question him to deter-
mine whether he was a police officer. He nevertheless
contends that the officers unreasonably extended the
duration of the investigative stop, thus violating his Fourth
Amendment rights. Thurman maintains that the badge and
identification that he initially showed the officers was
sufficient to confirm that he was an officer entitled to carry
a firearm.
   In evaluating the reasonableness of an investigation, we
consider whether “ ‘the police diligently pursued a means of
investigation that was likely to confirm or dispel their
suspicions quickly, during which time it was necessary
to detain the [person].’ ” Leaf v. Shelnutt, 

,
1092 (7th Cir. 2005), quoting United States v. Sharpe, 

, 686 (1985). The reasonableness of the detention
is determined considering the totality of the circumstances.

.
  Even taking the facts in the light most favorable to
Thurman, there is no basis on which a jury could find a
Fourth Amendment violation here. Thurman acknowl-
edges that the stop itself was proper, as he was wear-
ing civilian clothes and carrying a firearm in a store.
Thurman produced a badge that had no identifying infor-
mation, and which could have been stolen or fabricated.
Moreover, the firearm registration card that he provided did
nothing to dispel that suspicion. The card had been altered
in that the firearm serial number was whited out and
overwritten with a hand-lettered number. The identification
card provided by Thurman revealed that he was an em-
ployee of the Chicago Police Department, but did not
establish that he was an officer in that department and
No. 05-2940                                                 5

therefore entitled to carry a firearm. In order to confirm his
status, the Homewood officers continued the inquiry.
   One officer familiar with the 21st District at which
Thurman claimed to work, questioned him as to the
buildings surrounding the police station. That question was
another avenue explored to confirm or dispel the suspicion
of his status, because a person working at that station
would be familiar with the local geography. It failed to clear
Thurman only because the Homewood officer’s information
was outdated. The public housing buildings with which he
had been familiar had been razed since he worked at the
CHA, and therefore the question did not elicit the expected
answer. Moreover, the officers attempted to verify his
employment by telephone, but checked with District 21 of
the Illinois State Police instead of the 21st District of the
Chicago Police Department. There is no allegation that the
call to the state police was anything but a mistake. Because
it failed to elicit the information that would clear Thurman
to carry the firearm, the investigation continued. That
misstep does not transform the investigation from a
proper one to an unconstitutional one, as the focus is on
whether the officers were pursuing a means of investigation
likely to dispel or confirm their suspicions.
  Moreover, as soon as the officers were provided with the
number to the 21st District, they called the number and
confirmed that Thurman was an officer. His weapon was
then promptly returned and the officers departed.
  Thurman has simply failed to produce any evidence that
would demonstrate that the officers unreasonably extended
the duration of the investigation. All of the actions taken by
the officers were designed to elicit information as to
whether he was a police officer. Although Thurman believed
that they should have accepted his badge and initial tender
of identification, they were not constitutionally required to
do so. As previously noted, the badge could have been stolen
6                                               No. 05-2940

or fabricated, and that is apparently not an uncommon
occurrence. Moreover, the altered firearm card gave the
officers more reason to be cautious in making their determi-
nation as to his status. Even absent that, however,
Thurman failed to present any identification with his name
or photo, which identified him as a police officer.
  Thurman appears to fault the officers for not “getting
around” to asking for the 21st District phone number
earlier, stating that he provided the number when they
finally got around to asking for it, but there was nothing
preventing him from volunteering it earlier to resolve the
issue more expeditiously. As it was, the entire incident took
a total of 20-25 minutes by Thurman’s estimate (which we
assume for this appeal). Because all of the questioning and
the actions of the officer were likely to yield the needed
information regarding his status as a police officer, the
investigation did not violate Thurman’s Fourth Amendment
rights. Accordingly, the district court properly granted
summary judgment in favor of the defendant officers on the
Fourth Amendment claim. Because Thurman cannot
survive summary judgment on the substantive claim
against the individual officers, summary judgment was
proper for the Village of Homewood on his failure to train
claim as well. See Windle v. City of Marion, 

,
663 (7th Cir. 2003) (in order to recover damages from a
municipality under either a failure to train theory or a
failure to institute a municipal policy theory, the plaintiff
must prove that the individual officers are liable on the
underlying substantive claim); Tesch v. County of Green
Lake, 

, 477 (7th Cir. 1998) (same).
  Thurman raises an additional claim, however, stemming
from alleged conduct after the encounter at Home Depot
by the officers and an attorney acting on their behalf,
Gerald Zansitis. According to Thurman’s Second Amended
Complaint, after learning that they were being sued in this
action and with the intent of causing harm to Thurman
No. 05-2940                                                   7

because he had complained of their conduct, the officers
misused their office as Homewood police officers to per-
suade Zansitis “to make false and defamatory oral and
written statements” intended to prejudice Thurman in his
employment with the Chicago Police Department. Thurman
alleged that the conduct constituted a conspiracy actionable
under 42 U.S.C. § 1983 and defamation in violation of
Illinois law. The district court granted summary judgment
on the § 1983 claim, holding that Thurman failed to show
that the officers acted under color of law. The court chose
not to exercise supplemental jurisdiction over the remaining
state law defamation claim.
  Thurman asserts that his § 1983 claim is essentially one
of retaliation by the officers for his decision to file the
lawsuit based on the Home Depot incident. A cause of
action under § 1983 requires a showing that the plaintiff
was deprived of a right secured by the Constitution or
federal law, by a person acting under color of law.
    For the individual defendants to act “under color of
    state law” for § 1983 purposes means to “misuse [ ]
    power, possessed by virtue of state law and made
    possible only because the wrongdoer is clothed with the
    authority of state law. As a result, acts by a state officer
    are not made under color of state law unless they are
    related in some way to the performance of the duties of
    the state office.”
[citations omitted] Burrell v. City of Mattoon, 

,
649 (7th Cir. 2004), quoting Honaker v. Smith, 

, 484-85 (7th Cir. 2001). A private actor, such as
Zansitis, can have acted under color of law if the plaintiff
can establish that “(1) the private individual and a state
official reached an understanding to deprive the plaintiff of
her constitutional rights and (2) the private individual was
a willful participant in joint activity with the state or its
agents.” Hanania v. Loren-Maltese, 

, 356 (7th
8                                                 No. 05-2940

Cir. 2000). Thurman has failed to provide any evidence
from which a jury could conclude that the al-
leged defamatory conduct was undertaken under color of
law. In fact, Thurman has presented no evidence what-
soever in regard to this claim, even failing to identify the
defamatory statements, the context in which they were
made, or the nature of any communications between the
officers and Zansitis. As the district court pointed out, any
citizen may file a complaint against any Chicago police
officer, Chicago Municipal Code 2-84-430, and it appears
that the defamation claim is based upon such a complaint.
Therefore, there is nothing in the nature of the complaint
that indicates the use of a power “possessed by virtue
of state law and made possible only because the wrong-
doer is clothed with the authority of state law.” 

. Thurman cannot rest upon mere unsupported
allegations, but must come forward with some evidence that
a genuine issue of fact exists. Alexander v. City of South
Bend, 

, 554 (7th Cir. 2006). Thurman has
provided no evidence indicating that the defendants acted
under color of law, and therefore the court properly granted
the defendants’ motion for summary judgment.
  Finally, Thurman argues that the district court erred
in holding that supplemental jurisdiction was not proper
over the state law defamation claim because it did not form
part of the same case or controversy as the Home Depot
incident as required by 28 U.S.C. § 1367(a) for supplemen-
tal jurisdiction. We need not address this argument,
however, because that was merely an alternative holding of
the district court. The court first noted that all federal
claims had been dismissed and stated that it chose not to
invoke supplemental jurisdiction under 28 U.S.C. §
1367(c)(3). Section 1367(c)(3) assumes that a claim satisfies
the same case or controversy requirement of § 1367(a), but
grants to the district court the discretion to decline jurisdic-
tion where all federal claims have been dismissed. The
No. 05-2940                                             9

court exercised that discretion, and Thurman raises no
argument challenging that determination. Because the
court properly declined to exercise supplemental jurisdic-
tion under § 1367(c)(3), Thurman’s argument regarding the
court’s alternative holding is irrelevant.
 The decision of the district court is AFFIRMED.

A true Copy:
      Teste:

                       ________________________________
                       Clerk of the United States Court of
                         Appeals for the Seventh Circuit




                   USCA-02-C-0072—5-2-06