Plaintiff-Appellant Frederick S. Roger appeals pro se the district court’s dismissal for failure to state a claim for relief, pursuant to Fed.R.Civ.P. 12(b)(6), of Roger’s civil rights action, filed pursuant to 42 U.S.C. § 1983, against Jeb Bush, as Governor of the State of Florida (“Governor”); Christopher Reith, as a hearing officer in the CircuiVCounty Court in Broward County; and Jane/John Doe, as “respondeat superrior for Broward County’s Traffic Division.” 1 Roger argues on appeal that this dismissal was erroneous. For the reasons set forth more fully below, we affirm the court’s dismissal of Roger’s complaint.

Roger filed a pro se amended § 1983 complaint, asserting that the Governor, Reith, and Jane/John Doe denied him his civil rights, pursuant to the First, Fifth, Eighth, Ninth, and Fourteenth Amendments, by maliciously prosecuting him, and by convicting him of a traffic infraction after failing to bring this infraction to trial within 180 days of the issuance of the citation. Roger contended that his claim of malicious prosecution was based on the defendants (1) committing fraud and abuse of process, (2) failing to notify him of a decision, (3) falsifying documents, and (4) failing to calendar a motion. Roger also generally stated that the defendants discriminated against him because of his race.

In support of his complaint, Roger alleged the following facts. On July 18, 2000, a police officer with the City of Parkland, Florida, stopped Roger and issued him a traffic citation for making an improper U-turn. 2 Roger entered a plea of not guilty to the traffic infraction, posted a bond in the amount of $75, and returned to his residence in New York. Moreover, Roger filed an affidavit with the traffic court, explaining that he did not observe a no U-turn sign, and that his crying child had distracted him.

Roger contended that his trial for the infraction, which was scheduled to occur in *330 the County Court in and for Broward County, repeatedly was postponed, first from October 26, 2000, to January 4, 2001, and, subsequently, to March 7, 2001, and to May 10, 2001. On May 2, 2001, Roger filed in the traffic court a motion to dismiss the citation because he had not been tried within 180 days from its issuance, in violation of Rule 6.326 of the Florida Rules of Traffic Court. 3 On May 10, 2001, without setting Roger’s motion to dismiss on its calendar and in Roger’s absence, the traffic court conducted a trial on the traffic infraction and found Roger guilty.

Roger further contended in his complaint that he never received proof of this conviction. Instead, he received a document from the traffic court, notifying him that he had to attend driving school to avoid being arrested and having the infraction appear on his driving record. Roger responded by sending a letter to various state and county officials, accusing them of “racketeering.” Although the Clerk of the Court informed Roger in a letter that Marc Gold — the person Roger referred to as Jane/John Doe in his complaint — would review the matter, Roger never received a response from Gold. Roger also contended that his driving record does not reflect the infraction at issue in this case. 4

Roger generally argued in his complaint that the defendants violated his civil rights either by exceeding their authority in prosecuting his traffic infraction after the relevant 180-day period, or by failing to intervene or investigate. As relief, Roger sought (1) damages in the amount of $78,000, (2) injunctive relief in the form of an order “commanding defendants to stop and cease their activity,” 5 and (3) a declaration that the defendants denied him his civil rights.

The defendants responded by filing a motion to dismiss this amended complaint for failure to state a claim, pursuant to Fed.R.Civ.P. 12(b)(6). The defendants argued, among other things, that the complaint should be dismissed against Reith because (1) Reith was acting within his *331 discretionary authority as a hearing officer when he adjudicated Roger guilty, and (2) Roger had failed to show that Reith violated a clearly established constitutional right. Moreover, the defendants argued that, because the allegations against the remaining plaintiffs appeared to involve only lack of supervision, they also were entitled to immunity. In the alternative, the defendant argued that Roger’s complaint was barred by the Rooker-Feldman doctrine because federal courts, other than the Supreme Court, are barred from reviewing constitutional claims if the claims succeed only to the extent that the state court wrongly decided the issues before it. 6 The defendants also argued that the Eleventh Amendment was an absolute bar to Roger’s complaint to the extent he was seeking damages against the state or its agencies.

After Roger failed to respond to this Rule 12(b)(6) motion, the district court granted it. The court first determined that Reith was entitled to qualified immunity because (1) Reith had been acting within the scope of his discretionary authority as a hearing officer when he adjudicated Roger guilty; and (2) Roger had failed to allege a clearly established constitutional violation. The court also coneluded that, although Roger’s allegations against the Governor and Jane/John Doe were “not entirely clear,” the allegations appeared to relate to the defendants’ failures to supervise or intervene and, thus, also were barred under the doctrine of qualified immunity. Alternatively, the court determined that it should abstain from hearing Roger’s § 1983 because, under the Rooker-Feldman doctrine, Roger was seeking review of a state court’s final decision.

Roger is arguing on appeal that the court erred in granting the defendant’s motion to dismiss because the defendants failed to answer either his amended complaint, or to provide through discovery documents that contradicted the facts alleged in his complaint. Roger asserts that the dismissal was not warranted because Reith erred in failing to grant Roger’s motion to dismiss his traffic infraction after it was not tried within 180 days. He also generally asserts that the defendants were either directly or vicariously liable because (1) they exceeded the scope of their duties in prosecuting him, (2) Reith had no absolute immunity, and (3) Reith should have been disqualified “due to [his] malicious prosecution.” 7

*332 We review de novo a district court’s dismissal for failure to state a claim pursuant to Rule 12(b)(6). Magluta v. Samples, 375 F.3d 1269, 1273 (11th Cir. 2004). To the extent Koger is challenging the court’s dismissal prior to the defendants providing discovery, a complaint is subject to dismissal under Rule 12(b)(6) when the plaintiff “can prove no set of facts in support of his claim which would entitle him to relief,” or “when its allegations-on their face-show that an affirmative defense bars recovery on the claim.” See Marsh v. Butler County, Ala., 268 F.3d 1014, 1022 (11th Cir. 2001) (en banc) (citations and quotations omitted). “[Ujnsupported conclusions of law or of mixed fact and law have long been recognized not to prevent a Rule 12(b)(6) dismissal.” Id. at 1036 n. 16 (citation omitted). On the other hand, “[a]ll well-pleaded facts in plaintiffs complaint and all reasonable inferences drawn from those facts are taken as true.” McGinley v. Houston, 361 F.3d 1328, 1330 (11th Cir. 2004) (quotation omitted).

i. Heck v. Humphrey

To the extent Koger was seeking damages and declaratory relief, the Supreme Court held in Heck that:

[T]o recover damages for allegedly unconstitutional conviction or imprisonment, or for other harm caused by actions whose unlawfulness would render a conviction or sentence invalid, a § 1983 plaintiff must prove that the conviction or sentence has been reversed on direct appeal, expunged by executive order, dedared invalid by a state tribunal authorized to make such determination, or called into question by a federal court’s issuance of a writ of habeas corpus, 28 U.S.C. § 2254. A claim for damages bearing that relationship to a conviction or sentence that has not been so invalidated is not cognizable under § 1983.

Heck, 512 U.S. at 486-87, 114 S.Ct. at 2372. Thus, a plaintiff may not obtain damages under § 1983 if a judgment in his favor “would necessarily imply the invalidity of his conviction or sentence.” Id. Moreover, although the district court did not discuss Heck in its order granting the Rule 12(b)(6) motion to dismiss, we may affirm a decision of the district court “on any adequate ground, even if it is other than the one on which the court actually relied.” See Fishermen Against Destruction of Environment, Inc. v. Closter Farms, Inc., 300 F.3d 1294, 1296-97 (11th Cir. 2002) (citation and quotation omitted).

Liberally construing Roger’s amended complaint, the only constitutional claims he raised that were cognizable under § 1983 were the denial of his right to a speedy trial and malicious prosecution. See Tannenbaum v. United States, 148 F.3d 1262, 1263 (11th Cir. 1998) (“Pro se pleadings are held to a less stringent standard than pleadings drafted by attorneys and will, therefore, be liberally construed”). 8 To the extent he was arguing a speedy-trial claim, the Sixth Amendment guarantees that, “[i]n all criminal prosecutions, the accused shall enjoy the right to a speedy and public trial.” See U.S. Const. *333 amend. VI. We have concluded that, if a defendant’s constitution right to a speedy-trial has been violated, dismissal of an indictment, information, or complaint is mandatory under Fed.R.Crim.P. 48(b)(3). 9 United States v. Dunn, 345 F.3d 1285, 1297 (11th Cir. 2003), cert. denied, — U.S. -, 124 S.Ct. 2837, 159 L.Ed.2d 270 (2004).

To the extent Roger asserted a claim of malicious prosecution, a plaintiff seeking to establish such a violation in a § 1983 action must prove a violation of his Fourth Amendment right to be free from unreasonable seizures, in addition to the elements of the common law tort of malicious prosecution. Wood v. Kesler, 323 F.3d 872, 881 (11th Cir.), cert. denied, 540 U.S. 879, 124 S.Ct. 298, 157 L.Ed.2d 143 (2003). We have looked to both state and federal law for the elements of common law tort. Id. To allege this common law claim in Florida, a plaintiff must assert, among other elements, that the termination of the original proceeding constituted a bona fide termination of that proceeding in favor of the present plaintiff. Kingsland v. City of Miami, 382 F.3d 1220, 1234 (11th Cir. 2004).

Thus, in raising both of these constitutional claims, Roger essentially was challenging either the legality of his conviction or his sentence. A judgment in Roger’s favor in his speedy-trial claim would “necessarily imply the invalidity of his conviction.” See Heck, 512 U.S. at 486-87, 114 S.Ct. at 2372; see also Dunn, 345 F.3d at 1297. Similarly, judgment in Roger’s favor in his malicious-prosecution claim was dependent on a finding that the prosecution terminated in his favor. See Kingsland, 382 F.3d at 1234. Roger’s claims for damages and declaratory relief based on these constitutional violations, therefore, were barred under Heck.

To the extent Roger also was seeking injunctive relief in requesting an injunction “commanding defendants to stop and cease their activity,” the Supreme Court has determined that, despite the limitations of Heck, a plaintiff may still seek prospective injunctive relief, see Edwards v. Balisok, 520 U.S. 641, 648, 117 S.Ct. 1584, 1589, 137 L.Ed.2d 906 (1997). To obtain such relief, however, a plaintiff must show that the relief will not “necessarily imply” the invalidity of his conviction or sentence. See id., 520 U.S. at 648, 117 S.Ct. at 1589. Because Roger’s requested prospective relief would have “necessarily implied” that the defendants violated his speedy trial rights and/or maliciously prosecuted him and, thus, that his convictions were invalid, the court also did not err in dismissing Roger’s claims to the extent he was seeking injunctive relief. Accordingly, the court did not err in dismissing for failure to state a claim Roger’s § 1983 claims.

ii. Qualiñed Immunity

Even if we were to conclude that Heck was inapplicable, the district court properly determined that the defendants were protected under the doctrine of qualified immunity. “Qualified immunity offers complete protection for government officials sued in their individual capacities if their conduct does not violate clearly established statutory or constitutional rights of which a reasonable person would have known.” Kingsland, 382 F.3d at 1231 (quotation and marks omitted). “Qualified immunity represents a balance between the need for a remedy to protect citizens’ *334 rights and the need for government officials to perform their duties without the fear of constant, baseless litigation.” Id. Thus, it is “appropriate for a district court to grant the defense of qualified immunity at the motion to dismiss stage if the complaint ‘fails to allege the violation of a clearly established constitutional right.’ ” Gonzalez v. Reno, 325 F.3d 1228, 1233 (11th Cir. 2003) (quotation omitted).

To receive qualified immunity, “the public official must first prove that he was acting within the scope of his discretionary authority when the allegedly wrongful acts occurred.” Kingsland, 382 F.3d at 1232 (quotation omitted). The burden then shifts to the plaintiff to show that qualified immunity is not appropriate. Id. In determining whether the plaintiff has met his burden, courts must apply the following two-part test:

(1) “[t]aken in the light most favorable to the party asserting the injury, do the facts alleged show the officer’s conduct violated a constitutional right?” and (2) if a constitutional right would have been violated under the plaintiffs version of the facts, the court must then determine “whether the right was clearly established.”

Storck v. City of Coral Springs, 354 F.3d 1307, 1314 (11th Cir. 2003) (quoting Saucier v. Katz, 533 U.S. 194, 201, 121 S.Ct. 2151, 2156, 150 L.Ed.2d 272 (2001)). “[I]f no constitutional violation is established, then the officer prevails, and ‘there is no necessity for further inquiries concerning qualified immunity.’ ” Storck, 354 F.3d at 1314 (quotation omitted).

In the instant case, Koger’s allegations in his amended complaint reflect that the defendants were acting within the scope of their discretionary authority as a hearing officer, county official, and state official; thus, Koger had the burden of alleging a constitutional violation. See Kingsland, 382 F.3d at 1232. To the extent Koger was attempting to assert a claim of malicious' prosecution, he had to allege, as discussed above, that the prosecution terminated in his favor. See id. at 1234. Moreover, Koger had to allege that the defendants acted without probable cause. See id. Because Koger neither alleged facts showing that the prosecution terminated in his favor, nor that probable cause was lacking in the prosecution of his traffic infraction, he failed to assert a constitutional claim of malicious prosecution. See Marsh, 268 F.3d at 1036; see also Davila v. Delta Air Lines, Inc., 326 F.3d 1183, 1185 (11th Cir. 2003) (“conclusory allegations, unwarranted factual deductions or legal conclusions masquerading as facts will not prevent dismissal [for failure to state a claim]”), cert. denied, 540 U.S. 1016, 124 S.Ct. 568, 157 L.Ed.2d 430 (2003).

Furthermore, to the extent Koger was attempting to assert that he was denied his right to a speedy trial under the Sixth Amendment, factors to be considered in a speedy-trial claim include “(1) whether the delay before trial was uncommonly long; (2) whether the government or the defendant is more to blame for that delay; (3) whether, in due course, the defendant asserted his right to a speedy trial; and (4) whether the defendant suffered prejudice as a result of the delay.” United States v. Harris, 376 F.3d 1282, 1290 (11th Cir. 2004) (citations omitted). “The first factor serves a triggering function; unless some ‘presumptively prejudicial’ period of delay occurred, we need not conduct the remainder of the analysis.” Id. (quotation omitted). The delay at issue in this first factor — the time between the date of the indictment and the trial date — is considered “presumptively prejudicial” as it approaches one year. Dunn, 345 F.3d at 1296.

*335 Regardless, the Supreme Court has recognized that a defendant generally cannot establish a Sixth Amendment speedy trial claim, however long the delay, if the government pursued the prosecution with “reasonable diligence,” and the defendant fails to show that the delay resulted in “specific prejudice to his defense.” Harris, 376 F.3d at 1290 (quoting Doggett v. United States, 505 U.S. 647, 656, 112 S.Ct. 2686, 2693, 120 L.Ed.2d 520 (1992)). Moreover, we have determined that a defendant must demonstrate actual prejudice unless each of the first three factors “weights] heavily against the government.” Dunn, 345 F.3d at 1296. A defendant who must prove actual prejudice to establish a speedy trial claim can do so by showing (1) oppressive pretrial incarceration; (2) anxiety and concern resulting from the delay; or (3) the possibility that his defense will be impaired. Id. (citing United States v. Clark, 83 F.3d 1350, 1354 (11th Cir. 1996)).

Here, the delay between the issuance of the traffic citation at issue on July 18, 2000, and Roger’s trial for this offense on May 10, 2001, was approaching one year and, thus, arguably was “presumptively prejudicial.” See Dunn, 345 F.3d at 1296. Moreover, by filing his motion to dismiss, Roger asserted his right to a speedy trial before he was convicted. Nevertheless, Roger conceded in his affidavit in support of his motion to dismiss that his trial was not commenced prior to May 2, 2001, based on non-appearances by both parties. Most importantly, Roger, who was not incarcerated because of the traffic infraction, did not allege in his amended complaint that he suffered “actual prejudice” from this delay. See Dunn, 345 F.3d at 1296. Thus, the district court did not err in concluding that Roger failed to assert a constitutional violation of his right to a speedy trial, and that Reith also was entitled to qualified immunity as to this claim. See Storck, 354 F.3d at 1314.

Finally, to the extent Roger asserted that the remaining defendants were liable based on their failure to investigate, and to the extent that this claim may be construed as a due process claim under the Fourteenth Amendment, we determined in Vinyard v. Wilson, 311 F.3d 1340 (11th Cir. 2002), that, because substantive due process rights are created by the Constitution and “no amount of process can justify [their infringement],” a plaintiff had no substantive due process right to an investigation of a constitutional claim by a sheriff’s office. See id. at 1356. In addition, we concluded in Vinyard that the plaintiff was unable to show a procedural due process violation because, absent a showing by the plaintiff of federal or state law that gave her an entitlement to an internal investigation, there was no constitutionally protected liberty or property interest at stake in the case. See id. Similarly, in this case, Roger failed to identify in his amended complaint a federal or state law under which he was entitled to an internal investigation. Furthermore, although Roger arguably also asserted that the remaining defendants were vicariously liable, “supervisory officials are not liable under § 1983 for the unconstitutional acts of their subordinates on the basis of respondeat superior or vicarious liability.” See Smith ex rel. Smith v. Siegelman, 322 F.3d 1290, 1295 (11th Cir. 2003).

Accordingly, we conclude that he district court did not err in granting the defendants’ Rule 12(b)(6) motion to dismiss. 10 We, therefore, affirm.

AFFIRMED.