More preclusion law from the 7th Circuit

A valid final judgment on the merits is claim preclusive, but does not bar claims that accrue after a previous suit was filed.   The italicized word is important.  For example, suppose the plaintiff's second suit involves claims that accrued after she filed the first suit but before judgment was rendered in the first suit.  Addressing this issue, Judge Posner teaches his second preclusion lesson of the week in Smith v. Potter:

It is true that some of the alleged harassment that occurred after the plaintiff filed her first suit occurred before she dismissed the suit, and so, the government argues, she could have amended her complaint to add an allegation of that harassment.  But ... there is no legal duty to amend rather than bring a fresh suit, especially since a plaintiff has a right to amend her complaint only once without leave of court.  Suppose that a year into the case, with trial about to begin, the plaintiff experienced a fresh act of harassment.  The judge might quite understandably not want to allow her to amend her complaint to add the new allegation, because that might require additional discovery and so force postponement of the trial.  On the government's view, the judge would have to either allow the amendment, in order to prevent the bar of res judicata from cutting off the plaintiff's access to a remedy for the fresh harassment, or deny it and by doing so deny her any remedy.  Neither alternative is attractive.

--RR