Marco Allen Chapman wants to die by lethal injection after admitting he brutally killed two children and left their sister and mother for dead.

Now, the Kentucky Supreme Court is set to hear arguments on the legality of Chapman's request.

The case is unprecedented in Kentucky — posing the question of whether a defendant can waive all his rights and request an execution. It also has the unusual twist of putting prosecutors and Chapman on the same side — arguing for the death sentence to be upheld, while Chapman's court-appointed defense attorneys seeking to save Chapman from committing what they call "suicide by court."

"This is a defense lawyer's worst nightmare," said Michael Mello, a University of Vermont law professor and former lawyer for death row inmates in Florida.

The Kentucky Supreme Court set for oral arguments in the automatic appeal on April 12.

Chapman, who has declined multiple interview requests, pleaded guilty in December 2004 to killing 7-year old Chelbi Sharon and 6-year old Cody Sharon in their home in the northern Kentucky community of Warsaw. Chapman also admitted attacking 10-year-old Courtney Sharon, who played dead after being stabbed several times, then raping and trying to kill their mother, Carolyn Marksberry, during the August 2002 assault. A judge granted his request to be sentenced to death.

It is a policy of The Associated Press not to name victims of sexual assault in most cases; however Marksberry has discussed her ordeal in local and national television broadcasts.

Prosecutors say Chapman's attack was revenge for Marksberry advising a friend to end a relationship with Chapman. Immediately after the attacks, Chapman burglarized the home and fled to West Virginia, where he was arrested later that day.

Volunteering for a death sentence is not new. Since 1977, when Gary Mark Gilmore waived his appeals and stepped before a firing squad in Utah, 124 inmates in 26 of the 38 states with a death penalty law have waived appeals and asked to die. Nevada has had a dozen executions in that time, with 10 of them being inmates who volunteered. Texas, with 26 people volunteering, leads the nation in inmates giving up the fight against a death sentence, according to the Death Penalty Information Center in Washington, D.C.

One of the two people executed in Kentucky since 1976 — Eddie Lee Harper — waived the remainder of his appeals and was executed in 1999.

A second Kentucky Death Row inmate, Shawn Windsor, is attempting the same thing as Chapman. Windsor pleaded guilty in 2006 to killing his wife and son and asked for execution. He is on Kentucky's Death Row, but Chapman's case is further along in the automatic appeals process granted in all death penalty cases.

What makes Chapman's case groundbreaking, lawyers said, was his decision to waive trial, sentencing by a jury, and nearly beg to be sentenced to death. Professors who teach criminal law have found Chapman's case — and it's potential implications for future defendants — disturbing.

Michael Hoffheimer, a criminal law professor at the University of Mississippi, said a ruling giving deference to a client's decision to seek a death sentence could be troubling because it would take away multiple legal safeguards to ensure that a competent, guilty person is put to death. Without those safeguards, there's a chance someone who is not guilty, but suicidal, could be executed, Hoffheimer said.

"Permitting defendants to make decisions that increase the risk of wrongful convictions is bad policy," Hoffheimer said. "The rights to life and liberty are unalienable. They should be accorded greater weight than the right to control one's legal defense."

Cornell University law professor John Blume, who authored an analysis of death penalty volunteers for the University of Michigan Law Review, said attorneys have no obligation to aide a client in dropping appeals. But, Blume said, a court must make sure there are no issues about the defendant's guilt and that they are competent and "the desire to drop the appeals is not a desire to end their life but rather they are motivated by an acceptance of responsibility for their crimes."

Mello, who once represented notorious serial killer Ted Bundy, said the decision should remain that of the man on death row, provided he is competent. The reasons for the decision aren't as important as the decision being made rationally, Mello said.

"The heart of the matter is, whose life is it," Mello said. "I'm not one, who as a consequence of his actions, is going to spend his life in a tiny cage."

Chapman's court-appointed attorneys, Donna Boyce and Randall Wheeler, declined interview requests. Vicki Glass, a spokeswoman for the Kentucky Attorney General's Office, declined comment because the case is pending. Chapman has said several times that he is waiving his appeals and wants to be executed.

In 174 pages of briefs with the high court, Boyce and Wheeler argue that the trial judge mishandled the case and that Chapman was depressed and seeking to use court proceedings to commit suicide. They want a new sentencing hearing for Chapman after he's been treated for depression.

"Marco Chapman is committing suicide. He said he is," Boyce and Wheeler wrote. "This court must not allow this to happen."

Because Chapman was found competent multiple times, prosecutors said in briefs, his plea and sentence should be allowed to stand.

"The fact of the matter is that preferring death over life imprisonment is not state assisted suicide, just because death penalty abolitionist like to call it that," Assistant Attorney General David Smith wrote.