Frazier Glenn Miller
Frazier Glenn MillerReuters

A white supremacist wanted to explain to jurors on Monday his motive for killing three people at Jewish sites in suburban Kansas City, but a judge told him the first phase of the capital murder trial was to focus solely on whether he committed the crimes and not why, reports The Associated Press (AP).

Frazier Glenn Miller, who is representing himself, made it only a few words into the first sentence of his opening statement before assistant District Attorney Chris McMullin objected and jurors were removed from the courtroom, according to the news agency.

Miller, 74, of Aurora, Missouri, had told Johnson County Judge Thomas Kelly Ryan earlier that he twice offered to plead guilty to first-degree murder if prosecutors would take the death penalty off the table, but they refused. He started to tell jurors of those failed offers before McMullin spoke up.

"If he wants to confess, that's fine, but we can't talk about things not in evidence," the prosecutor said after jurors left the room. "If the state said that, there would be an immediate mistrial. We don't want a mistrial."

At multiple hearings leading up to the trial, Miller had admitted that he killed William Corporon, 69, and Corporon's 14-year-old grandson, Reat Griffin Underwood, at the Jewish Community Center in Overland Park, and Terri LaManno, 53, at the nearby Village Shalom retirement center on April 13, 2014.

None of the three was Jewish, but Miller has said in the past he was trying to target Jewish people.

In fact, the prosecutor began his opening statement on Monday’s with what he said was a quote from Miller as he was sitting in a police car in a parking lot where he was found shortly after the shootings.

"My name's Glenn Miller, I am an anti-Semite, I hate godd*mned Jews. How many did I get?" Miller said, according to the prosecutor.

McMullin graphically described the wounds Corporon and Underwood suffered as they were hit in the head with shotgun blasts at point-blank range. He spoke of LaManno being frozen in fear as Miller pulled a shotgun from the trunk of his car after a different gun failed to fire.

Miller said he is suffering from chronic emphysema and wanted to kill Jewish people before he died. He pleaded not guilty to the charges against him in March, but later said he's ready to plead guilty to all charges to avoid a lengthy trial.

The prosecution's first witnesses testified Monday about what they saw at the Jewish Community Center.

Paul Temme said he was planning to work out at the center's gym when he heard loud noises and a woman warned that someone was shooting. He told jurors he saw a car driving away and tried to chase it to get a license plate, but the car turned and started coming toward him.

Temme said he thought one shot was fired at him, but Miller corrected him on cross-examination that there were two, according to AP.

In an interview last November, Miller expressed his surprise and regret at not having managed to kill any Jews.

"I was convinced I was dying then," he told The Kansas City Star, recalling the moment he was admitted to a hospital with breathing difficulties. "I wanted to make damned sure I killed some Jews or attacked the Jews before I died."