Lawyers for a Death Row inmate said Tuesday they want to depose a doctor and nurse involved in Missouri executions so they can argue their case that a drug combination used to kill condemned prisoners is unconstitutionally cruel punishment.

But the state has blocked it — in part over concerns medical personnel would be harassed.

The defense team is not seeking a reprieve of the death penalty for convicted killer Michael Taylor of Kansas City. Attorney Donald Verrilli, Jr., of Washington, told a federal appeals court panel in St. Louis that the three-drug cocktail used in Missouri and around the country could result in a "horrible, excruciating death" if the anesthesia doesn't take effect or wears off.

Similar arguments are being made in death penalty cases around the country.

But the defense in this case offered an alternative: a single high dose of barbiturate, said to be constitutionally permissible and attain the same result.

Verrilli asked the three-judge panel to send the case back to U.S. District Court in Kansas City to be heard by the original judge assigned to the case.

In January, a hearing to weigh the cruel punishment argument was transferred from Judge Scott O. Wright to Judge Fernando Gaitan because Gaitan's schedule could accommodate it more quickly. At the close of the hastily convened, two-day hearing, Gaitan ruled that Missouri's execution protocol is constitutionally permissible.

Taylor's defense team said it needs the testimony of the doctor and nurse involved in state executions to argue the case. The defense also wants to present a witness who couldn't make the hearing in Gaitan's court.

The defense said that Sri Melethil, an expert in the science of how drugs act in the body over time, would rebut the state's witness, Dr. Mark Dershwitz.

Dershwitz has testified that more than enough of the first drug — the sedative sodium pentothal — is given to a condemned prisoner before the second is administered. He has said that it would be "horrible" to administer the second and third drugs to an awake person.

Taylor and his co-defendant Roderick Nunley pleaded guilty to first-degree murder, forcible rape, armed criminal action and kidnapping for the March 1989 killing of 15-year-old Ann Harrison.