Prosecutors and defense lawyers in the Colorado theater shooting will head back to court Wednesday in advance of a crucial hearing in the case.

State District Judge William B. Sylvester has told both sides to appear before him to make sure everything is ready for next week's preliminary hearing, when prosecutors will outline their case against the defendant, James Holmes.

At the conclusion of the preliminary hearing, Sylvester will decide if the evidence is sufficient to put Holmes on trial.

Holmes is charged with killing 12 people and wounding 70 on July 20 in a movie theater in the Denver suburb of Aurora. Prosecutors say he opened fire during a midnight showing of the Batman movie "The Dark Night Rises."

Holmes faces multiple counts of first-degree murder and attempted murder and hasn't yet entered a plea. His lawyers have said he suffers from mental illness.

The preliminary hearing, which starts Monday, will give the public its first officially sanctioned look at much of the evidence against Holmes.

Sylvester imposed a gag order shortly after Holmes' arrest barring attorneys and investigators from speaking publicly about the case, and many documents have been sealed.

The University of Colorado, where Holmes was a graduate student, has also been tight-lipped about the case.