The avowed white supremacist has told various media outlets, including The Associated Press that he is dying from emphysema and went to the sites with the intent to kill Jewish people.
He is set to face the death penalty for the murders of 14-year-old Reat Griffin Underwood, his grandfather – 69-year-old physician Dr. William Lewis Corporon, and 53-year-old Terri LaManno. All three victims where Christians, and only one person targeted by the shooting was Jewish.
In the wake of the attack, Prime Minister Benjamin Netanyahu sent his condolences to the victims families, and said: "We condemn the shootings which, according to all the signs, were perpetrated out of hatred for Jews."
Frazier is scheduled to be in court Wednesday for a hearing on motions in his case, one asking a judge to let him stay in the courtroom during recesses and another to suppress certain evidence.
Also known as Frazier Glenn Cross, Miller got permission last month from Johnson County District Judge Kelly Ryan to fire his attorneys and represent himself.
The judge did rule however, that the attorneys would stay involved in the case on a stand-by basis and could be restored as Miller's counsel if he gets kicked out of the courtroom during his trial, or decides he wants them back.
The judge remained composed throughout the hearing as Miller repeatedly interrupted him, declaring that he wanted to be a "martyr" and that the only way he would be able to speak his mind in court was to represent himself.
Miller filled a motion Tuesday, asking that he be allowed to remain in the courtroom during recesses. Because of his chronic emphysema, he uses a wheelchair with an oxygen tank at his side.
He also wants the judge to suppress statements made by witnesses and physical evidence collected at the crime scene, which the state opposes.
Miller's trial is scheduled for August, and he has insisted on a speedy trial over the objections of his attorneys.
Last month, Johnson County District Attorney Steve Howe told the court that Miller's attorneys had twice sought a deal in which he would plead guilty if the death penalty were removed from the table, but the prosecutor rejected both requests.
Miller the founded the Carolina Knights of the Ku Klux Klan and later the White Patriot Party in his native North Carolina , and is a Vietnam veteran.