SCRANTON, Pa. — An attorney representing an inmate charged in the murder of a guard inside a Pennsylvania prison says his client “is guilty of murder beyond all doubt.”

Jessie Con-ui, 40, could face the death penalty if convicted of first-degree murder in the February 2013 stabbing death of 34-year-old corrections officer Eric Williams at the Canaan federal prison in Waymart.

Con-ui, who is serving 25 years to life for a 2002 gang initiation murder in Arizona, killed Williams without excuse or justification, defense attorney David Ruhnke said Monday in his opening statement. “Jessie is guilty of murder beyond all doubt,” he said.

Ruhnke said he doesn’t plan to challenge the government’s evidence and will call no witnesses during the trial phase, but he assured jurors that lawyers would later present evidence on whether Con-ui should face execution or life in prison.

Assistant U.S. Attorney Francis Sempa earlier went through a detailed description of the attack. Williams was stabbed more than 200 times with two homemade shanks, kicked and stomped on the face, head and neck, Sempa said.

Prosecutors allege that Con-ui stopped the attack in a prison housing unit to walk over to a shower, clean a cut on his hand and wrap it before continuing. He later paused to chew a piece of gum he took from the dying guard’s pocket before returning to his cell, authorities said.

Investigators have said Con-ui was angry after the guard ordered a search of his cell the previous day. They said officers who followed a bloody trail to Con-ui’s cell reported seeing him holding a clear, plastic knife and asked if he killed Williams. They said he responded, “Yes, disrespect issue.”

Since the slaying, Con-ui has been at the super-maximum security prison in Florence, Colorado.