ATLANTA --- Jurors began deliberating Thursday on the fate of a gunman who says he was legally insane when he killed four people in a shooting spree that began at a downtown Atlanta courthouse.

Brian Nichols, 36, faces the death penalty in the fatal shootings of a judge, a court reporter, a deputy and a federal agent in the 2005 rampage. He has pleaded not guilty by reason of insanity, claiming he was gripped by a delusional compulsion that he was a slave rebelling against authority.

The jurors did not reach a verdict Thursday and were expected to continue deliberating today.

They have several options, including convicting or exonerating him, finding him not guilty by reason of insanity or guilty but mentally ill.

The last option would require the prison system to evaluate Mr. Nichols and determine a punishment.

If the jury returns either of the guilty verdicts, it must decide whether he deserves the death sentence. If he is found not guilty by reason of insanity, he will likely go to a state mental hospital.

Mr. Nichols' attorneys and a psychologist say phone conversations while he was in jail were evidence of his delusions.

A psychiatrist who testified for the state said he found Mr. Nichols was mentally ill but would not diagnose him as delusional.