The man charged with carrying out a deadly rampage at a U.S. movie theater in July is due to appear in court Monday for the beginning of preliminary hearings to determine if his case will go to trial.

Prosecutors have filed 142 counts against James Holmes for the shooting attack that killed 12 people and wounded 58 others in Colorado.

The hearing is expected to last a week, with prosecutors publicly outlining their case against Holmes for the first time. A judge will then decide whether to proceed to trial.

Prosecutors have not yet determined if they will seek the death penalty.

Authorities say Holmes attacked the theater during a midnight screening of the Batman film The Dark Knight Rises, throwing tear gas canisters inside before opening fire on the audience.

The 25-year-old was a Ph.D. student in neuroscience, but withdrew from his program a month before the shootings.

His lawyers have said he is mentally ill, and court records indicate they may call witnesses at the preliminary hearing to testify about his mental state.