Former Saints star Darren Sharper is stuck with Orleans Parish Criminal Court Judge Karen Herman, because he pleaded guilty in her court and it remains up to her to ensure he holds up his end of the deal and cooperates with prosecutors.

The two pals who allegedly joined him in drugging and raping several women are fighting tooth and nail to have their trials held in front of a different judge, however. The clear and unflattering implication is that the odds would be stacked against them if they came up before Herman.

The proposition that justice is blind does indeed not always hold up well at Tulane and Broad, where some judges are regarded as oozing with sympathy for defendants. Herman, who ascended to the bench after a career as a prosecutor, is certainly not in their number.

But nobody has alleged demonstrated partiality in her conduct of the court, and the Metropolitan Crime Commission ranks her just about every year as the most efficient of the criminal court judges, measured by the time taken to wind up felony cases. Given that defense attorneys may sometimes welcome a delay in proceedings, they cannot be expected to share the MCC’s high opinion of Herman.

Sharper’s co-defendants, former St. Bernard Parish Sheriff’s Deputy Brandon Licciardi and former steakhouse waiter Erik Nunez, clearly could not cite prejudice as grounds for Herman’s recusal, so their attorneys hit on the idea of challenging the system whereby cases are allocated to the various divisions. They claim that it enables District Attorney Leon Cannizzaro to direct a case to a favorite judge, whereas due process requires random allotment.

They are ahead right now, an appeal court having ruled the allocation system unconstitutional. But the state Supreme Court heard arguments on the matter Monday, when four of the seven justices seemed inclined to side with the prosecution. Those four justices — Greg Guidry, Scott Crichton, Jeannette Knoll and Marcus Clark — are certainly not likely to look askance at Herman’s professional background, for they used to be prosecutors too.

Trying to remove a judge regarded as unsympathetic is always a risky move, because failure may leave defendants with even more reason to fret. Nunez and Licciardi would hardly have challenged the constitutionality of the system if it hadn’t thrown up a judge they assume is ill-disposed towards them. But they must hope they were wrong, and they haven’t made matters worse, if the Supreme Court leaves the case in her court.

In fact, there is no reason to doubt they will get a fair trial. Indeed, during Monday’s oral arguments, Knoll said she could not see why anyone would want to avoid such a fine judge as Herman.

But the constitutional question must be resolved regardless of which judge is chosen. For the last several years, cases are allocated according to the date of the alleged crime, but complications arise when that cannot be pinpointed or where multiple offenses are committed over a long time frame.

In those cases, the DA sets a range of dates and chooses a first of the month from among them. Thus, according to the appeal court, the system is susceptible to manipulation by the DA, who can choose a date when he knows a friendly judge will be up.

There is no proof that Cannizzaro deliberately steered these cases to Herman, but the mere scope for manipulation constitutes denial of due process, according to the appeal court. Constitutional purity will, however, not be easy to achieve, because, as a couple of justices observed from the bench, nobody has yet devised a purportedly random allocation system that is entirely proof against a fix.

The allocation rules have been all the harder to observe because it has not always easy to determine what they are. The criminal court judges in 2011 adopted a rule requiring that cases should be assigned according to the date of “first report,” whatever that means, but it did not apply here because it was not published until August of this year, a month after the appeal court hearing.

Regardless, when and wherever Nunez and Licciardi come up for trial, they may be sure Sharper will testify freely. If he doesn’t, Herman will be on hand with the power to make him do 20 years in prison instead of the 10 he currently faces.

James Gill’s email address is jgill@theadvocate.com.