here is an explanation from the latimes.
Lindsay Lohan must return to court April 22  for a preliminary hearing on a felony grand theft charge for allegedly  stealing a necklace from a Venice jewelry store and to decide whether  she was in violation of her probation in a previous drunk driving case.
 Judge Keith Schwartz said Judge Stephanie Sautner will preside over the April hearing.
 Lohan 
arrived shortly after 9 a.m. wearing a beige dress, black tights and a long ponytail.
 Schwartz admonished Lohan to present any additonal information under  seal to keep the information away from the prying eyes of tabloid  reporters.
 "Thankfully this case doesn't involve military secrets," he said. "I  can't belive TMZ and Radar Online. These guys ought to be in the foreign  services. They ought to hook up with the CIA and work for them.
 "I don't even tell my wife what's going on so I can't understand how  they find out. It's not fair to either side to have these things leaked  out in dribs or drabs. It doesn't benefit anybody, so please try to keep  every offer I made confidential, and that's that."
                                    Earlier, video cameras were lined up thickly from the street by the  courthouse to the entrance. A bevy of photographers jostled each other  for a better vantage point. News vans clogged the parking lots. Lohan is facing a felony grand theft charge for allegedly stealing a necklace from a Venice jewelry store.
 Lohan has been seeking a deal that would keep her out of jail, but at  her last court appearance Schwartz made it clear that would not be an  option -- at least in his courtroom.
 If convicted of grand theft, she could face significant jail time. If  she decides not to accept the plea deal, her case will be set for a  preliminary hearing in front of another judge to determine whether there  is enough evidence for her to stand trial.
radaronline sez
The Mean Girls star, 24, was given the option to return before  Judge Schwartz on Friday, March 25 when, at that time, she can plead  either ‘guilty’ or ‘no contest’ to the felony grand theft charge. The  judge has previously told Lindsay that if she does accept a plea deal,  it will involve some jail time.
 If Lindsay does not accept a plea deal and instead intends to fight  the charge, Judge Schwartz said she will have to face fellow Judge Stephanie Sautner for a preliminary hearing on April 22.
Judge Schwartz said that at that hearing, the judge will decide if  there is enough evidence to bound her over for trial on the felony grand  theft charge related to the theft of a $2,500 necklace from a jewelry  store in Venice Ceach, CA. Judge Schwartz also said that at that time,  her parole violation will be dealt with also.
 At one point in the hearing, Judge Schwartz acknowledged  RadarOnline.com and other news outlets for their aggressive reporting in  this story.