“Arguable Probable Cause” Solidified: Tentative Identifications, Qualified Immunity, and the Limits of Fabricated-Evidence Claims after Mack v. City of Chicago

I. Introduction

The Seventh Circuit’s decision in Kiontae Mack v. City of Chicago, No. 23-2662 (7th Cir. Aug. 13 2025), addresses the aftermath of an ultimately unsuccessful criminal prosecution. After being acquitted of murder and robbery charges, Kiontae Mack sued five Chicago police officers and the City under 42 U.S.C. § 1983 for illegal pre-trial detention, fabrication of evidence, coerced confession, and malicious prosecution. The district court granted summary judgment to the defendants; the Court of Appeals affirmed.

Key issues included:

Whether a tentative show-up identification creates “arguable probable cause” shielding officers from liability.
Whether post-arrest police reports and use of a single photograph constituted evidence fabrication.
Whether an alleged coerced confession that was never used against the defendant in court can support a Fifth or Fourteenth Amendment claim.
How an acquittal affects malicious-prosecution and due-process claims anchored in allegedly fabricated evidence.

II. Summary of the Judgment

Judge Lee, writing for a unanimous panel (Rovner, Brennan, Lee), held:

The officers had at least arguable probable cause to detain Mack, based on the victim’s tentative identification and Mack’s own confession; therefore, qualified immunity bars the Fourth Amendment detention and malicious-prosecution claims.
An acquittal, by definition, means no conviction or imprisonment resulted from the allegedly fabricated evidence; Mack’s Fourteenth Amendment fabrication claim therefore fails.
A coerced-confession claim under the Fifth Amendment requires that the confession be used against the defendant in a criminal proceeding; because Mack’s confession was never introduced, that claim fails.
The chain of causation was broken by a grand-jury indictment supported by independent evidence; post-indictment detention therefore could not be attributed to the police officers.
Summary judgment for all defendants was therefore affirmed.

III. Analysis

A. Precedents Cited and Their Influence

Manuel v. City of Joliet, 580 U.S. 357 (2017) – Established that Fourth Amendment protection extends to pre-trial detention both before and after legal process begins. The panel used Manuel to frame Mack’s detention claim.
McDaniel v. Polley, 847 F.3d 887 (7th Cir. 2017) & Holloway v. City of Milwaukee, 43 F.4th 760 (7th Cir. 2022) – Both cases held that even a tentative eyewitness identification can create probable cause. The court leaned heavily on these authorities to find “arguable probable cause.”
Coleman v. City of Peoria, 925 F.3d 336 (7th Cir. 2019) – Articulated the “high bar” for fabrication claims and the presumption of probable cause arising from an indictment. It guided rejection of Mack’s fabrication theory.
Chavez v. Martinez, 538 U.S. 760 (2003) – Clarified that a Fifth Amendment violation occurs only when a coerced statement is used in court. This precedent doomed Mack’s self-incrimination argument.
Thompson v. Clark, 596 U.S. 36 (2022) – Recognized malicious-prosecution claims under the Fourth Amendment; yet the court found them barred because probable cause—at least arguable—existed.

B. Court’s Legal Reasoning

Qualified Immunity & “Arguable” Probable Cause
Qualified immunity protects officers unless a constitutional right is “clearly established.” Under Huff v. Reichert (7th Cir. 2014), officers need only “arguable” probable cause. The court ruled that:
- The victim’s immediate, albeit tentative, identification of Mack during a show-up placed officers within the arguable-cause zone.
- Mack’s own confession (even if later disputed) reinforced that belief.
Break in Causation at Indictment
Under Reed v. City of Chicago, a grand-jury indictment—unless procured by fraud—breaks the causal chain. Independent evidence (confession + eyewitness) supported the indictment; hence post-indictment detention was not attributable to the officers.
Fabrication Claim Fails Without Conviction
Citing Patrick v. City of Chicago, the court stressed that a due-process fabrication claim centers on wrongful conviction. Because Mack was acquitted and the reports never introduced, no due-process injury occurred.
Self-Incrimination Claim Requires Courtroom Use
Following Chavez, the panel emphasized that even a coerced confession does not violate the Fifth Amendment unless the prosecution uses it in court. Mack’s confession stayed out of every proceeding; the claim therefore collapsed.

C. Impact on Future Litigation

Heightened Shield of “Arguable Probable Cause.” By reaffirming that even tentative identifications suffice, the court makes it harder for civil-rights plaintiffs to circumvent qualified immunity in eyewitness-based arrests.
Clarified Boundaries of Fabrication Claims. Plaintiffs acquitted at trial must now show a different form of post-trial liberty deprivation or other damages; mere pre-trial detention will likely be analyzed instead under the Fourth Amendment framework.
Reinforced Requirement of “Use” for Fifth-Amendment Violations. Defense counsel should insist that involuntary statements never see the inside of a courtroom; their exclusion, as here, effectively nullifies later § 1983 liability on self-incrimination grounds.
Practical Guidance for Police Procedures. Officers can reasonably rely on show-up identifications but should still document the tentative nature to avoid later fabrication claims. Prosecutors remain encouraged to corroborate such identifications independently.

IV. Complex Concepts Simplified

Qualified Immunity: A legal shield protecting government officials unless they violate clearly established law. Think of it as “legal safe-harbor” for gray-area decisions.
Probable Cause vs. Arguable Probable Cause: “Probable cause” means enough facts to reasonably believe a crime was committed. “Arguable” probable cause is a slightly lower threshold giving officers wiggle room for reasonable mistakes.
Show-up Identification: A quick, on-scene procedure where a lone suspect is presented to a witness. Courts dislike them but allow their use if promptly conducted and not overly suggestive.
Fabricated-Evidence Claim: A civil action alleging police created false evidence. It succeeds only when the plaintiff proves officers knowingly planted falsehoods that caused a wrongful conviction.
Self-Incrimination Clause “Use” Requirement: Even if police coerce a confession, the constitutional violation crystallizes only when that statement is introduced in court proceedings against the accused.

V. Conclusion

Mack v. City of Chicago cements the proposition that a victim’s tentative identification, combined with corroborating circumstances, delivers “arguable probable cause” sufficient to cloak officers in qualified immunity. It further clarifies that:

Acquittal forecloses fabrication-of-evidence claims under the Due Process Clause absent a conviction-based injury.
Grand-jury indictments generally sever causation for wrongful-detention claims unless fraudulently obtained.
Fifth Amendment self-incrimination claims demand actual courtroom use of the coerced statement.

In sum, the opinion narrows the litigation avenues available to defendants who were acquitted yet spent significant time in pre-trial detention. Going forward, plaintiffs will need either to attack the absence of even “arguable” probable cause at the moment of arrest or to identify concrete post-trial liberty deprivations to escape the formidable barrier of qualified immunity.