The suspect in the Feb. 12 rampage on Guam that left three slain and several others wounded pleaded not guilty Wednesday by reason of mental illness.

Chad Ryan De Soto, 21, entered the plea through his lawyer at an arraignment hearing in the Superior Court of Guam.

Judge Alberto Tolentino subsequently ordered a psychological evaluation of De Soto and set his next court appearance for March 20.

De Soto's mother and other relatives attended the session, the former breaking into tears as soon as she saw the suspect being brought into the court. The family remains barred from seeing De Soto as the investigation continues on the case, officials said.

De Soto was indicted by a grand jury last week on three counts of aggravated murder and 12 counts of attempted aggravated murder. Investigators allege that on Feb. 12, De Soto ran down six people with his car, crashed it into a building and then stabbed eight people after getting out of the vehicle.

Two Japanese tourists were killed at the scene, and a third died later. Twelve other people, 11 of them from Japan, were wounded in the attack in the busy tourist district of Tumon. De Soto is being held on $3 million bail. The aggravated murder charge carries a penalty of life in prison without parole.