Ashcroft Can Be Sued Over Misuse of Material Witness Statute

There are limits to the immunity of people in law enforcement.

Basically, it comes down to the fact that you can sue someone for being wrongly arrested or imprisoned, but not for being wrongly indicted or prosecuted, so a 3 judge federal appellate panel, by a vote of 2½ to ½, there was a partial concurrence by one of the judges, said that a Lawsuit against John Ashcroft over the misuse of the material witness statute can proceed.

Basically, the purpose of the material witness statute is to ensure that a witness who might otherwise become unavailable, i.e. skip town, will be available to the authorities, but John Ashcroft used it to detain people on his whim, which the judges describes as, "repugnant to the Constitution, and a painful reminder of some of the most ignominious chapters of our national history."

Because a prosecutor cannot be sued for a prosecution, but he can be for an arrest.

Glenn Greenwald's take on this is a good read.