The Supreme Court has ruled that former Attorney General John Ashcroft cannot be sued over his role in the post-9/11 arrest of an American Muslim who was never charged with a crime.

By a 5-3 vote Tuesday, the court said Ashcroft did not violate the constitutional rights of Abdullah al-Kidd, who was arrested in 2003 under a federal law intended to make sure witnesses testify in criminal proceedings.

But even the justices who disagreed about the constitutional issue agreed that Ashcroft could not be personally sued for his role in al-Kidd's arrest. The court reversed a federal appeals court ruling that denied Ashcroft immunity from liability in this case.