This decision starts out with some promise, as the plaintiff challenges the constitutionality of a New York law that empowers SPCA staffers with governmental investigatory functions. That's a potentially interesting issue. But, as resolved by the Court of Appeals, the case does not turn on that issue. It devolves into a discussion about an obscure abstention principle governing when federal courts may decide cases that raise similar issues to those raised in state court.
The case is Kanciper v. Suffolk County Society for the Prevention of Cruelty to Animals, decided on July 8. The plaintiff is president of a horse rescue organization. Someone complained about "equine abuse" on the horse farm. An SPCA staffer threatened plaintiff with prosecution, but the case was closed for lack of probable cause. The SPCA got a search warrant about seven months later on another animal abuse complaint, leading to plaintiff's indictment. The animal abuse charges were then dismissed. Hence this lawsuit challenging the SPCA's authority to do things like this.
At the same time, plaintiff sued the SPCA in state court on various state law theories, like abuse of process and fraud. That claim is pending. The federal court dismissed plaintiff's Section 1983 claims on a "claim splitting" theory because the state lawsuit would be preclusive in the federal action, i.e., her federal and state claims arose from the same facts and she could have brought the Section 1983 claims in state court with her other state claims.
If you are still reading this, then you are a litigation junkie who cares about abstention and federal jurisdiction. So let's get technical. In some instances, federal courts can abstain from hearing claims if they are more appropriately handled by the state courts. The state and federal courts also do not want to resolve duplicative litigation. There is such a doctrine as "claim splitting," which asks "whether the first suit, assuming it were final, would preclude the second suit." The district court threw out plaintiff's case under the "claim splitting" theory, but that was in error. Claim splitting does not apply here because the first filed case was brought in state court, not federal court. What applies instead is a federal court's general obligation to hear cases over which it has jurisdiction. The Second Circuit (Calabresi, Cabranes and Parker) says, "While plaintiffs generally have no right to maintain two separate actions involving the same subject matter at the same time in the same court and against the same defendant, as between state and federal courts, the rule is that the pendency of an action in the state court is no bar to proceedings concerning the same matter in the federal court having jurisdiction."
In other words, state and federal courts can simultaneously handle separate but related actions raising different claims. That is what plaintiff is doing here. The only way a federal case like this can be dismissed is if the parallel state court litigation could result in the comprehensive disposition of litigation and abstention would conserve judicial resources. Defendants may raise that theory in the district court on remand.