Carsten Quinlan v. Washington County

• Court: Court of Appeals for the Eighth Circuit
• Decided: March 17, 2026
• Docket: 25-2661
• Status: Unpublished

Opinion

United States Court of Appeals For the Eighth Circuit ___________________________

No. 25-2661 ___________________________

Carsten James Quinlan; A.G.Q.; E.D.Q.; L.E.Q.

lllllllllllllllllllllPlaintiffs - Appellants

v.

Washington County; City of Woodbury; Kim Richardson; Hailey Dornfeld; Keshini Ratnayake; Tom Wedes; Mathew Stephenson; Chris Murphy; Unknown John and Jane Does

lllllllllllllllllllllDefendants - Appellees ____________

Appeal from United States District Court for the District of Minnesota ____________

Submitted: March 12, 2026 Filed: March 17, 2026 [Unpublished] ____________

Before SHEPHERD, KELLY, and ERICKSON, Circuit Judges. ____________ PER CURIAM.

Carsten Quinlan appeals after the district court1 dismissed his pro se civil action and denied his motion for leave to file a supplemental complaint. Upon careful de novo review, we affirm.

We conclude that the district court did not err in dismissing the action, see Schriener v. Quicken Loans, Inc., 774 F.3d 442, 444 (8th Cir. 2014) (grant of motion to dismiss reviewed de novo), because the facts included in Quinlan’s operative complaint and exhibits show his arrest was based on probable cause, see Brown v. City of St. Louis, 40 F.4th 895, 903 (8th Cir. 2022) (Fourth Amendment claims based on warrantless arrest fail when probable cause supported arrest and initiation of prosecution), and because appellees did not infringe on his due process rights, see Folkerts v. City of Waverly, 707 F.3d 975, 980–81 (8th Cir. 2013) (to state substantive due process claim, plaintiff must show fundamental right was violated by official conduct that shocks conscience); see also Mitchell v. Dakota Cnty. Soc. Servs., 959 F.3d 887, 897 (8th Cir. 2020) (in child removal cases, due process requires hearing “promptly after removal”).

We also conclude the district court properly denied Quinlan’s motion for leave to supplement, because his proposed supplements would have been futile. See Schriener, 774 F.3d at 446 (denial of leave to amend reviewed for abuse of discretion, but underlying conclusion that amendment is futile reviewed de novo).

The judgment is affirmed. See 8th Cir. R. 47B. ______________________________

1 The Honorable Katherine M. Menendez, United States District Judge for the District of Minnesota.

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