I suspect the criminal contempt finding is being sought to defeat any claim of qualified government immunity in the civil suits, but since I'm not a civil lawyer, that's just a guess.

I've commented/blogged here about this issue before, but I can't remember where so rather than just link to it I'll synopsize. In order to get to make all the points necessary, the briefs on motions to dismiss regularly bump up against the page limits in the Courts where they're filed - the law on this is deep and requires that much space, so you are getting the thumbnail sketch only - not legal advice.  

I've defended about 10 civil cases where the prosecutor was sued by a criminal defendant for alleged violations of civil rights or tortious conduct.  These cases are losers for the plaintiffs.  I never lost one.  I never heard of a prosecutor's side losing one save in one particular case where there was actual go-to-prison criminality by the prosecutor.  Even there the law is so pro-prosecutor the civil judges had to bend the facts around the law to get relief to a person whose civil and constitutional rights were grossly violated by a criminal in prosecutor's clothes (and in a county where the head criminal court judge - a hang 'em high type - was corrupt and also went to prison for it).  The cases are usually disposed of on motions to dismiss - even before discovery gets started.

My opinion is that lawyers who undertake these cases either (a) get in before they have any idea of how pro-prosecutor the law is, (b) are taking the case more to make the client happy - even when they lose, they can say they tried.  Only in very rare cases - like the Duke case - do the criminal defendants have a chance of winning the suit.

The short version is this.  The prosecutor is entitled to at least three species of immunity from civil liability and, even, against the prosecution of a civil case.  These are:

(1) absolute prosecutorial immunity;

(2) qualified immunity;

(3) judicial proceedings immunity.

There are several more, too, which I discuss later.  

But, before you even get to the issue of immunity, there's an initial hurdle - you already have to be proven innocent.  The ordinary criminal defendant/civil plaintiff (this does not apply in the Duke case for reasons which will become obvious - they were never convicted of anything), has to have successfully overcome - through reversal on appeal, vacating on habeas, or pardon or commutation - the criminal judgment of conviction.  If the civil cause of action would even imply the invalidity of the judgment of conviction and the judgment of conviction still stands unreversed, the parts of the case which imply invalidity are to be dismissed.  This rule is courtesy of Justices Thomas, Scalia, et als. in a 1994 case called Heck v. Humphrey.  Since most cases against prosecutors are for violations of civil rights which sound in the old tort of "malicious prosecution", and malicious prosecution has as one of its "essential elements" that the criminal defendant was innocent (or, said another way, was prosecuted without there being probable cause for it), you can see that Heck v. Humphrey will gut a large percentage of claims, where the defendant's civil rights were violated but the judgment of conviction still stands.

NB and a little OT  - If any of you want to see how the detainee cases are viewed by Justice Thomas (in case you didn't already know), read this from his concurrence in Heck:  "It has long been recognized that we have expanded the prerogative writ of habeas corpus and 1983 far beyond the limited scope either was originally intended to have."  Again, this was 1994:  pre-AEDPA and pre-Bushie.  The problem, as he sees it, is not too little habeas or accountability.  Rather, it's that there is too much.

But, the parts of the case which survive Heck v. Humphrey then encounter the prosecutor's immunities.  You usually address them in this order:

(1) absolute prosecutorial immunity - This comes from the US Supreme Court case of Imbler v. Pachtman, a 1976 case out of California where the prosecutor (knowingly) got a conviction of the wrong guy for a murder and had him sentenced to death.  (The death sentence was later reduced to life;  go read the case to see all the gory details.) In short, if the prosecutor's conduct which allegedly gives rise to liability involves the individual performing any of the duties of a prosecutor - meeting witnesses, presenting evidence, trying cases, representing to the court, deciding which evidence to put on or produce in discovery, withholding evidence, etc., then the prosecutor is deemed to be acting as a prosecutor.  When a prosecutor is acting as a prosecutor, he is absolutely immune.

Imbler and prosecutorial immunity means there is absolute immunity from civil liability for things like:  Brady violations, knowingly putting on perjured testimony, withholding relevant evidence, tampering with witnesses, securing indictments against known innocents (e.g., by giving the grand jury a partial view of the facts - the one which supports an indictment), misconduct (i.e., lying) to support warrants, lying to the judge, trial misconduct.  The list goes on, but you get the idea - the examples I list are from reported cases.

Anything which survives absolute immunity then gets to address -

(2) qualified immunity - this is the same immunity any other law enforcement person gets against civil rights claims.  The question is, in short, whether a reasonable law enforcement official in the position of the defendant knew or should have known that the conduct allegedly giving rise to the liability was unconstitutional/ a violation of the plaintiff's civil/constitutional rights.  This would apply to any conduct of the prosecutor where he was not acting in the core functions of a prosecutor.  Such things as press conferences that go beyond a mere "we have arrested X and charged Y, look at the pile of guns, money and dope we took" are about the closest a prosecutor ever gets to liability (and those are probably immune depending on the words used).  The scope of qualified immunity keeps getting larger, as every time Scalia and his buddies get their hands on a case, they find in favor of law enforcement (viz. the recent car-chase case).

Then you address -

(3) judicial proceedings immunity - this is the immunity given to lawyers, judges, witnesses and all the other personnel involved in courtroom activity, so they can say bad things about defendants and witnesses and do the investigating they have to do, in order to try cases effectively.  The scope of this immunity is defined by state law, so I won't go further.

These usually have the effect of knocking out all claims against a prosecutor under the Civil Rights Act (42 USC sec. 1983).  

If the case survives Heck and the immunities, then you get to look at whether the suit was brought in a timely manner, and against the right defendant.  Lately, the justices have been monkeying around with redefining "accrual" of a cause of action, i.e., the time when a person first has a right to sue.  Once the cause of action "accrues", the clock on the statute of limitations starts ticking.  IIRC, they recently decided (within the past year) that, for false arrest the cause of action accrues at the time of the seizure - not the time it's determined favorably to the defendant.  

Juxtapose, then, the rule of Heck v. Humphrey and the "accrual" rule.  With requirements for starting suit which are that short and criminal court delays, it is entirely likely that a wrongly arrested defendant will have to sue the prosecutor while the prosecution is still going on and, if the criminal defendant is (wrongly) convicted, then successfully appeal that conviction all within the short 1 or 2 or 3 years (it varies by state) that most statutes of limitations run, so as to satisfy Heck.  And, in the criminal case, the prosecution will surely appeal to a higher court, preventing the judgment from becoming "final", in the event the criminal defendant wins on appeal and is simultaneously suing the prosecutor.  

This is, quite deliberately, turning into a big Catch-22.  (And you wondered why Barbara Comstock, Mary Matalin and all the other Scooter Libby apologists were so strident and urgent in their message?  Beyond intra-Repug loyalty.  They know that once he's in the system, he's f'd.  They know because they helped build it.)

Then you address claims grounded in state law.  

He may also be entitled to immunity:

(4) under N.C.'s version of its Tort Claims Act That's a state law issue which I don't have any knowledge about other than to say that most states' TCAs have immunity for public employes except where the act in question is willful, criminal, or outside the scope of employment.  

Again, this is a state law issue I won't address because these Tort Claims Acts and their annotations usually merit a whole book unto themselves.  My guess is that the lacrosse players' lawyers are going strictly under state law-based claims, as federal civil rights claims will go nowhere fast, and the criminal contempt finding may open the door to state law liability for Nifong.

Then, depending on the State's constitutional structure and the place the prosecutor plays in it, he might get yet another bite at immunity -

(5) Under the Eleventh Amendment, there can be immunity from federal civil rights suits under particularized circumstances through a narrow, but growing, area of Eleventh Amendment law.  This is really subtle and involved, and I won't get into it here other than to say it involves a detailed analysis of the place of the prosecutor in the State's constitutional structure.  Since most lawyers never really have occasion to deeply analyze this and since most courts have not had the opportunity to analyze it (other than in the more common contexts of pay disputes or authority disputes), this is a fertile field for pushy lawyers defending prosecutors.  To their credit, most judges won't go or get this far because they (a) avoid constitutional questions whenever possible and (b) know that if they did it would mean eradication of any relief against many governmental officials under Section 1983.

Finally,

(6) Rooker-Feldman.  In appropriate cases, I also used to drive plaintiffs (and their lawyers) nuts by invoking the Rooker-Feldman doctrine in particular cases to eliminate subject-matter jurisdiction.  There was a Supreme Court decision last year (i.e., several years since I did these cases) in which the scope of Rooker-Feldman was narrowed, so I haven't looked at whether my syllogism would continue to apply (and I won't share it because it was my original idea - and wickedly powerful, too.).

Immunity is addressed before discovery begins.  Only the claims which survive immunity are proper fodder for discovery.  (Which, BTW, is why Deadeye Dick has still not sat down for his deposition in the Plame v. Cheney, Libby, et al. civil case.)

Oh, yeah.  One other thing.  Even if the criminal defendant/civil plaintiff should win the arguments on immunity in his suit against the prosecutor, he's got a series of hurdles ahead of him before the discovery process even begins.  The normal rule in federal court, and also in many states' courts, is "no interlocutory appeals".  An "interlocutory appeal" is one which comes before all issues as to all parties have been decided and incorporated in the judgment, in other words, one before the end of the case in the trial court.  

There are several exceptions to that rule, but the one most germane here is that decisions of the trial court on issues of immunity are not subject to the "no interlocutory appeals" rule.  In fact, interlocutory appeals are encouraged on immunity issues, to help get rid of meritless cases at an early stage and avoid burdening public servants with the demands of litigation.  So, once the trial judge says the case can go forward, the prosecutor can then appeal immediately.  

Making matters worse, the standard of review on immunity issues is "de novo" - which means that the trial judge's decision is not relevant to how the appellate court sees it.  The appellate court gets a fresh slate to write on and, these days, takes the opportunity to make the law even more draconian.

OK?

Usually, the only reason money gets paid on these cases is "political".  For whatever political reasons which may be germane to the individual situation, the local government wants to avoid the backlash which would come from taking a hard line defending an egregious case of misconduct.  And that's why they pay - not because they fear being held liable.  Because if they take a hard line, they almost invariably will never be held liable.