Independent Investigations Break the Cat’s Paw: Seventh Circuit Clarifies Comparator Rules and Causation in Age Discrimination Claims

Introduction

In Ronald Gaines v. Thomas J. Dart, the U.S. Court of Appeals for the Seventh Circuit affirmed summary judgment against a 69-year-old assistant chief in the Cook County Sheriff’s Office who alleged age discrimination in violation of the Fourteenth Amendment (via 42 U.S.C. § 1983), the Age Discrimination in Employment Act (ADEA), and the Illinois Human Rights Act (IHRA). The case centers on whether alleged ageist animus by a non-decisionmaker supervisor can be imputed to the ultimate decisionmaker under a “cat’s paw” theory of liability, and what kind of comparator evidence suffices under § 1983 and the ADEA.

Judge Jackson-Akiwumi, writing for a panel that included Chief Judge Sykes and Judge Kirsch, held that an employer’s independent, corroborated investigation and multi-level review can break the causal chain required to impose liability under a cat’s paw theory. The opinion also clarifies that while § 1983 Equal Protection claims require a comparator outside the protected class, ADEA plaintiffs may rely on significantly younger comparators who can themselves be over 40, though the district court’s contrary assumption in this case was harmless.

The parties are:

• Plaintiff-Appellant: Ronald Gaines, former Assistant Chief of the Electronic Monitoring (EM) Unit within the Cook County Sheriff’s Office.
• Defendants-Appellees: Carmen Ruffin (Gaines’s supervisor, sued in her individual capacity under § 1983) and Sheriff Thomas J. Dart (sued in his official capacity under the ADEA and IHRA). Cook County was named solely for indemnification.

Core issues:

• Whether Gaines presented sufficient evidence of age-based disparate treatment under § 1983, including a proper comparator and causation.
• Whether “cat’s paw” liability applies when the decisionmaker relies on an internal investigation allegedly tainted by a biased subordinate.
• Whether Gaines established a prima facie case and but-for causation under the ADEA/IHRA, under both McDonnell Douglas and the holistic Ortiz framework.

Summary of the Opinion

The Seventh Circuit affirmed summary judgment for the defendants on all claims. On the § 1983 Equal Protection claim against Ruffin, the court held that Gaines failed to identify appropriate comparators (he offered only other older officers who also allegedly suffered age discrimination) and failed to establish causation under a cat’s paw theory because the Sheriff’s Office of Professional Review (OPR) conducted an independent investigation that uncovered “independently sufficient reasons” for termination, and the ultimate decisionmaker (Chief of Intergovernmental Affairs Adriana Morales) independently reviewed that record.

On the ADEA and IHRA claims against the Sheriff, the court held that Gaines’s claims failed under both McDonnell Douglas and Ortiz. He could not show he was meeting the employer’s legitimate expectations, and he failed to present comparators who received more favorable treatment. The court corrected the district court’s misstatement that ADEA comparators must be under 40 (that is not required), but found the error harmless because Gaines’s comparators were not probative of disparate treatment. Considering the evidence “in a single pile” under Ortiz, the court concluded that alleged ageist comments by a non-decisionmaker and the timing of a complaint did not overcome the independent, corroborated reasons for the termination.

Analysis

Precedents Cited and Their Influence

• Johnson v. Accenture LLP, 142 F.4th 536 (7th Cir. 2025): The court views facts in the light most favorable to the nonmovant at summary judgment. This set the posture for the court’s factual recitation.
• Vassileva v. City of Chicago, 118 F.4th 869 (7th Cir. 2024) and Kinney v. St. Mary’s Health, Inc., 76 F.4th 635 (7th Cir. 2023): Reinforce de novo review and the “genuine dispute” standard, guiding the court’s summary judgment analysis.
• Reinebold v. Bruce, 18 F.4th 922 (7th Cir. 2021): Articulates elements of a § 1983 Equal Protection age discrimination claim—intentional different treatment, because of class membership, not rationally related to a legitimate state interest—framing the § 1983 inquiry.
• Barnes v. Board of Trustees of Univ. of Illinois, 946 F.3d 384 (7th Cir. 2020) and Kuhn v. Goodlow, 678 F.3d 552 (7th Cir. 2012): Emphasize causation and that the defendant must have caused or participated in the adverse action, which drove the court’s analysis of Ruffin’s role.
• Alston v. City of Madison, 853 F.3d 901 (7th Cir. 2017): Establishes that a plaintiff can show differential treatment via statistics or similarly situated comparators—used to reject Gaines’s comparator showing.
• Cat’s paw line: Matthews v. Waukesha County, 759 F.3d 821 (7th Cir. 2014); Smith v. Bray, 681 F.3d 888 (7th Cir. 2012); Taylor v. Ways, 999 F.3d 478 (7th Cir. 2021): Recognize cat’s paw liability and its applicability in § 1983 cases, permitting Gaines’s theory in principle.
• Sinha v. Bradley University, 995 F.3d 568 (7th Cir. 2021) and Vesey v. Envoy Air, Inc., 999 F.3d 456 (7th Cir. 2021): Define cat’s paw proximate cause and hold that independent, corroborated reasons break the chain—central to rejecting Gaines’s causation theory.
• Staub v. Proctor Hospital, 562 U.S. 411 (2011) and Staub, 560 F.3d 647 (7th Cir. 2009), rev’d: Provide the seminal cat’s paw rule and recognize that decisionmaker independence defeats imputation of bias—heavily relied upon for the “independently sufficient reasons” concept.
• McDaniel v. Progress Rail Locomotive, Inc., 940 F.3d 360 (7th Cir. 2019) and Martino v. MCI Communications Services, Inc., 574 F.3d 447 (7th Cir. 2009): Clarify that a decisionmaker need not be a “paragon of independence”; it suffices that they are not wholly dependent on a single source.
• Vega v. Chicago Park District, 954 F.3d 996 (7th Cir. 2020): Shows when a cursory review is too superficial to be independent; distinguished here because the OPR process did not have the similar procedural flaws and had multi-level review.
• Woods v. City of Berwyn, 803 F.3d 865 (7th Cir. 2015): The employer’s investigation can break the causal chain—echoed in the court’s ultimate holding.
• Teruggi v. CIT Group/Capital Finance, Inc., 709 F.3d 654 (7th Cir. 2013) and Zaderaka v. Illinois Human Rights Commission, 545 N.E.2d 684 (Ill. 1989): IHRA claims are analyzed like federal age claims—used to treat ADEA/IHRA together.
• Tyburski v. City of Chicago, 964 F.3d 590 (7th Cir. 2020): ADEA requires but-for causation—important constraint for Gaines’s statutory claims.
• McDonnell Douglas Corp. v. Green, 411 U.S. 792 (1973) and Vichio v. US Foods, Inc., 88 F.4th 687 (7th Cir. 2023): Provide the burden-shifting framework and the court’s dual-path analysis (McDonnell Douglas and Ortiz).
• O’Connor v. Consolidated Coin Caterers Corp., 517 U.S. 308 (1996) and Hartley v. Wisconsin Bell, Inc., 124 F.3d 887 (7th Cir. 1997): ADEA comparators need only be “significantly younger,” not outside the protected class—used to correct the district court’s comparator misstatement.
• Ortiz v. Werner Enterprises, Inc., 834 F.3d 760 (7th Cir. 2016): All evidence considered “in a single pile” to assess discriminatory intent—used to reject Gaines’s aggregate showing.
• Brooks v. Avancez, 39 F.4th 424 (7th Cir. 2022); Bagwe v. Sedgwick Claims Management Services, Inc., 811 F.3d 866 (7th Cir. 2016); Egonmwan v. Cook County Sheriff’s Department, 602 F.3d 845 (7th Cir. 2010): “Stray remarks” jurisprudence; decisionmaker linkage required—applied to diminish the probative value of Ruffin’s comments.
• Biolchini v. General Electric Co., 167 F.3d 1151 (7th Cir. 1999): Even an imprudent investigation does not imply discrimination absent evidence of differential treatment because of age—supports affirmance under Ortiz.

Legal Reasoning

• Section 1983 Equal Protection (against Ruffin):
  • Comparator failure: The court required Gaines to show he was treated differently than a similarly situated person outside the protected class (for equal protection purposes). Gaines submitted affidavits from six older officers who also alleged they were targets of the same ageist supervisor. That evidence might show animus, but not differential treatment. Without either statistical proof or a valid comparator, the claim cannot proceed.
  • Cat’s paw causation failure: Although the record contained multiple age-related remarks by Ruffin, she was not the decisionmaker; Morales was. The court assumed animus arguendo, but held that OPR’s investigation (interviews, vehicle GPS analysis cross-referenced against EM assignments, work-log review, and corroboration by Lt. Collins) and Morales’s command-channel review supplied independently sufficient, corroborated grounds for termination. Under Vesey and Staub, such independence breaks the causal chain and defeats proximate cause.
  • Key factual anchors for independence: Gaines’s admission that he went to the doctor during duty hours without approval; corroboration that he was in uniform and using a county vehicle; lack of radio contact; minimal entries in the unit’s system; no body-worn camera footage indicating patrol activity. Challenges to GPS granularity or the “boathouse” inference did not undermine the cross-referenced findings or the multiple independent bases for termination.
  • Decisionmaker independence: Morales need not be “a paragon of independence.” It sufficed that she was not wholly dependent on a single source and conducted her own review of the investigative file. The court distinguished Vega, noting no analogous procedural deficiencies and multiple levels of review.
• ADEA and IHRA (against the Sheriff in official capacity):
  • Frameworks applied: The court analyzed under both McDonnell Douglas and Ortiz.
  • McDonnell Douglas—no prima facie case:
    • Legitimate expectations: The OPR findings—unchallenged in material part—showed Gaines was not meeting reasonable expectations (present during duty hours, documenting work, supervising field officers).
    • Comparators: The district court misstated that ADEA comparators must be under 40. The Seventh Circuit corrected the law: ADEA plaintiffs may use comparators who are over 40 if they are “significantly younger” (O’Connor; Hartley). The error was harmless because Gaines still failed to identify any similarly situated younger employee who engaged in comparable conduct but was treated better.
  • Ortiz—aggregate evidence not probative of age as but-for cause:
    • Ruffin’s comments, while arguably ageist, were by a non-decisionmaker and not linked to Morales’s termination decision.
    • Temporal proximity between a remark and an OPR referral could not overcome the independent, corroborated grounds documented by OPR and reviewed by Morales.
    • A single reference to an anticipated retirement date in the OPR report did not tie age to the termination decision, given the otherwise evidence-based findings.
    • No evidence suggested that the employer investigated differently because of age (Biolchini). On this “single pile” view, the record still pointed to non-discriminatory reasons as the but-for cause of termination (Tyburski).

Impact

• Cat’s paw doctrine—strong reaffirmation of an “independent investigation” safe harbor:
  • Public and private employers who conduct multi-source, corroborated investigations—and whose decisionmakers perform at least some independent review—have a potent defense against cat’s paw liability. The opinion collects Seventh Circuit and Supreme Court authorities and applies them rigorously.
  • Practically, employers should ensure:
    • Documented interviews of multiple witnesses, particularly those without alleged bias.
    • Objective corroboration (e.g., GPS data, system logs, camera footage) and cross-referencing with job-related assignments.
    • Layered review (investigator, supervisory approvals, and a separate decisionmaker’s review).
• Comparator requirements—clarified distinction between § 1983 Equal Protection and ADEA:
  • For § 1983 Equal Protection age claims, plaintiffs must identify a similarly situated person outside the protected class (i.e., meaningfully younger, typically under 40) who was treated more favorably. Submitting co-workers who were also allegedly harmed by the same bias is not a valid comparator strategy.
  • For ADEA claims, comparators need only be “significantly younger,” even if over 40; the key is relative age gap and similar circumstances. This guidance corrects a recurring misstep in trial courts.
• Investigations and “stray remarks”:
  • Biased comments by non-decisionmakers retain limited probative value unless tied to the adverse action, especially where an independent investigation exists. Plaintiffs should build evidentiary bridges showing the decisionmaker relied on the biased subordinate’s tainted facts without independent corroboration.
  • Employers should train managers to avoid comments about retirement and age; even if ultimately non-dispositive, such remarks are often litigated and can increase litigation risk.
• Procedural discipline matters:
  • Employees who skip investigatory interviews or fail to rebut internal findings may find it harder to survive summary judgment. Here, Gaines’s absence from the OPR interview undercut attempts to create triable disputes about what occurred.
  • The opinion underscores that suspicion about data (e.g., GPS “granularity”) must be backed by competing evidence; speculative attacks on methodology are insufficient absent material factual disputes.

Complex Concepts Simplified

• Cat’s paw theory: When a biased subordinate, lacking final authority, manipulates a decisionmaker into taking adverse action. Liability attaches if the subordinate’s bias proximately causes the decision and the employer does not conduct an independent, corroborated investigation that breaks the causal chain.
• Comparator: A co-worker similarly situated in key respects (same supervisor, similar role, similar rules violated) who was treated differently. Under § 1983 Equal Protection, plaintiffs typically must point to someone outside the protected class; under ADEA, the comparator must be “significantly younger,” not necessarily under 40.
• But-for causation (ADEA): Age must be the reason why the employer acted; if the same decision would have occurred for independent, non-discriminatory reasons, the claim fails.
• McDonnell Douglas framework: A structured method of proof—prima facie case; employer articulates a non-discriminatory reason; plaintiff shows pretext. If any element fails (e.g., meeting expectations or valid comparators), the claim falters.
• Ortiz holistic approach: The court considers all evidence collectively—direct and circumstantial—to see if discrimination can reasonably be inferred, without rigid categories.
• Independent investigation “breaks the chain”: If an employer’s investigation gathers corroborated, unbiased facts and the decisionmaker performs a bona fide review, any subordinate bias typically cannot be imputed to the employer.
• IHRA alignment with ADEA: Illinois courts and the Seventh Circuit analyze IHRA age claims like ADEA claims, so federal standards guide both.

Conclusion

Gaines v. Dart reinforces two practical pillars in age discrimination litigation. First, cat’s paw liability is curtailed where an employer conducts a documented, corroborated investigation and the ultimate decisionmaker reviews and relies on independently sufficient reasons for discipline. The Seventh Circuit’s application of Staub, Vesey, and related precedents leaves little room for imputing a supervisor’s bias when those safeguards are present.

Second, the decision clarifies comparator doctrine across legal regimes. For § 1983 Equal Protection claims, plaintiffs must identify similarly situated individuals outside the protected class who were treated better. For ADEA claims, comparators may be over 40 if they are significantly younger, but plaintiffs still must show better treatment under similar circumstances. The district court’s contrary ADEA assumption was harmless here, but the appellate correction is an important reminder for trial courts and practitioners.

Ultimately, the court concluded that Ruffin’s remarks and the timing of her complaint could not overcome the OPR’s multi-source investigation and Morales’s independent command-channel review. The record established non-discriminatory, corroborated reasons for termination that would have led to the same outcome regardless of age. For employers, the case illustrates best practices that defeat cat’s paw claims; for employees, it underscores the need for robust comparator evidence, participation in internal investigations, and proof linking alleged bias to the ultimate decision.