There are ways to stop people from re-litigating their cases in federal court after they lose in state court. One way is the Rooker-Feldman doctrine, an esoteric rule that says federal courts cannot independently review state court judgments. Rooker-Feldman only applies when you're a "state court loser," which is why it doesn't apply in this case.
The case is Green v. Mattingly, decided on October 21. "State court loser" is language deriving from Second Circuit case law. It means what it says. If you lost in state court, under Rooker-Feldman, there is no federal court relief. Since state courts are able to resolve constitutional issues, it is no argument that federal courts are more qualified to do so.
In Green, the City of New York took plaintiff's child away on suspicion of child neglect. Green's husband slapped her child, and the Administration for Children's Services moved against her in Family Court. Green claimed that ACS authorities lied about her, but Family Court granted an order temporarily removing the child. But on further consideration, Family Court changed its mind because there was no imminent risk to the child's life or health. Green accepted an "adjournment in contemplation of dismissal," which means the charges are formally dropped if she followed certain conditions for a year.
Can Green now sue the child protective authorities under the Civil Rights Act in federal court? Sounds like a great case; she lost her child for four days allegedly because of governmental misconduct. Except for the Rooker-Feldman doctrine. The district court said Rooker-Feldman means Green can't sue in federal court because the state court did initially rule against her, and there was no final adjudication of the case in that the case was conditionally dismissed. This ruling was incorrect.
As the Court of Appeals (Miner, Cabranes and Rakoff, D.J.) notes, "the Rooker-Feldman doctrine applies only to federal actions brought by 'state-court losers,' and plaintiff is not a state-court loser." There was no final order of disposition removing Green's child, and she also reversed the temporary order removing her child. "She did not 'lose' in state court." Moreover, Green is not asking federal court to sit in judgment of a state court ruling. Rather, "[t]he only conceivable 'judgment' against plaintiff -- the temporary removal of her child -- has already been undone." Put another way, Rooker-Feldman would only apply if the Family Court ruled against Green for good and she brought a civil rights case in federal court to get her child back. As that's not the case here, Green's case may proceed in federal court.