A Kansas capital murder case involving a white supremacist who is dying of emphysema poses some unusual challenges for a district attorney pursuing the death penalty for the first time.

Johnson County District Attorney Steve Howe has twice rejected offers from Frazier Glenn Miller's attorneys to have Miller plead guilty to killing three people at two Jewish community centers last year in exchange for taking the death penalty off the table.

Howe says he believes Miller's alleged crimes deserve the most severe punishment. Kansas hasn't executed anyone in 50 years, however, and there's virtually no chance the 74-year-old will be the next. Critics say Howe's insistence appears to be aimed solely at scoring political points, with taxpayers picking up the tab.

"No death sentence they impose on this guy is ever going to be carried out. He was terminally ill and that's why he did this in the first place," said Sean O'Brien, a University of Missouri-Kansas City law professor who has defended dozens of death penalty cases since 1983.

Miller does not deny gunning down Dr. William Lewis Corporon, 69; his 14-year-old grandson, Reat Griffin Underwood; and 53-year-old Terri LaManno at two Jewish centers in the Kansas City suburb of Overland Park, Kansas, on April 13, 2014. He said he felt it was his duty to kill Jewish people before he died; he didn't know all three were Christians. And last week, Miller submitted a motion for acquittal in which he called the shootings justified.

Still, the Aurora, Missouri, man has pleaded not guilty and has insisted on his constitutional right to a speedy trial, which is to begin Aug. 17. Since the state is seeking the death penalty, it's unclear whether he would be allowed to plead guilty because of Kansas' ban on assisted suicide.

Several states have laws forbidding a defendant from pleading guilty when a death sentence is a possibility, and it's also not allowed under the federal Uniform Code of Military Justice. Kansas has no law addressing that specific issue.

"Yes, there is a question of whether pleading guilty and getting the death sentence violates suicide laws," said John Blume, a Cornell Law School professor who is director of the Cornell Death Penalty Project. "But why does that matter? Despite the language differences, the end result is the same."

Miller's attorneys, who were ordered by the judge to remain as standby counsel after Miller fired them last month, have repeatedly said an August trial date does not give them time to build a competent defense. Johnson County District Judge Kelly Ryan has issued a gag order barring attorneys from discussing the case, which Howe cited in declining to comment.

Howe, a Republican, was first elected as district attorney in the state's most populous county in 2008, then ran unopposed in 2012 and hasn't announced his intentions for 2016. Both of his predecessors also served as Kansas attorney general, but Howe hasn't publicly expressed an interest in that position.

One of Howe's counterparts in Missouri, Platte County prosecutor Eric Zahnd, said elected prosecutors either reflect the values of their communities or they don't get re-elected. But they don't take death penalty decisions lightly, he said, nor make them for political gain.

"Some murders are so terrible that they cry out for capital punishment," he said.

Miller told The Associated Press last month that his respiratory condition is getting worse and he's undergoing six breathing treatments a day.

"I've thought about killing myself in here, but I can't figure out how to do it," said Miller, who added that he'd plead guilty, even with the death penalty a possibility, as long as he gets a chance to justify his actions before the court at sentencing.

As for pursuing a death sentence against someone unlikely to survive long enough to go through the mandatory appeals process, Zahnd said: "If we knew a murder defendant had cancer with a life expectancy of just six months, would that make a one-year sentence appropriate? I think not."