Brian Nichols made the statement before he had met with an attorney. But Superior Court Judge Hilton Fuller said he will leave it up to a jury to decide whether Nichols made the statement voluntarily and how much weight it should be given.
Nichols, 34, is accused of killing Judge Rowland Barnes and a court reporter at the Fulton County Courthouse in 2005, and a sheriff's sergeant who chased him outside. A fourth victim, a federal agent, was later killed at his home. Nichols surrendered the next day after allegedly taking a woman hostage.
Nichols has pleaded not guilty, though authorities say he confessed in a three-hour statement to police.
Nichols' trial is scheduled for Jan. 11. Prosecutors are seeking the death penalty.