DENVER -- An inmate was convicted Thursday of killing his cellmate and using his entrails to taunt guards. He will now fight for his life as the same federal jury decides whether he should be executed.

After a four-week trial, the seven-woman, five-man jury deliberated two days before convicting William Sablan, 42, of first-degree murder in the death of Joey Jesus Estrella, 33.

Sablan showed no reaction as a courtroom staffer asked the jurors one-by-one to confirm they voted for the verdict.

Sablan and his cousin, Rudy Sablan, 47, are the first federal defendants in Colorado to face the death penalty since Oklahoma City bomber Timothy McVeigh. They were charged with killing Estrella on Oct. 10, 1999, after a night of drinking and fighting in the cell they shared at the federal penitentiary in Florence.

The trial to determine Sablan's punishment will begin Monday. Attorneys expect that trial to take about three weeks.

"I also want to thank the staff of the US Attorney's Office and the FBI for devoting long hours to ensure that justice was done. They deal with difficult cases every day, and they should be recognized for their efforts," said U.S. Attorney Troy Eid. "The government now looks toward preparing for the penalty phase of the trial."

Rudy Sablan's trial date hasn't been set.

Eid said called it "an extremely hard case" but said the outcome was just.

William Sablan's attorneys declined comment outside the courtroom.

Other inmates testified that the Sablans and Estrella had been smoking, playing cards and drinking homemade wine before a fight broke out the night of the killing. One inmate said he heard a fight and then heard a man struggling for breath.

Prosecutors said Rudy Sablan strangled Estrella with a headphone cord and that William Sablan used a prison-issue disposable razor to slash Estrella's neck. An autopsy showed Estrella bled to death and that some of his organs were removed after he died.

Early in the trial, prosecutors showed jurors a videotape shot by prison guards after they saw the carnage inside the cell. The tape showed William Sablan holding up Estrella's internal organs and making obscene gestures. Blood flowed under the cell door, and an "S" had been written in blood on the cell wall.

The razor believed to have been used in the crime was sitting next to Estrella's body early in the video but was missing later and was never found. Prosecutors said they believe Rudy Sablan flushed it down the toilet while telling William Sablan to block guards' view into the cell.

Defense attorneys argued that William Sablan had a history of mental illness, brain injuries and post-traumatic stress disorder that left him unable to control his impulses and deliberately kill Estrella.

Defense witnesses testified Sablan suffered at least two falls and a machete attack that left him brain-damaged.

Defense attorney Nathan Chambers blamed prison guards for lapses that allowed the inmates access to homemade wine, for placing three men -- including William Sablan, who had a history of violent crime -- in a cell designed for two and for failing to respond when an alarm button was pushed in the cell.

William Sablan, a native of Saipan in the Northern Mariana Islands, has a criminal history dating to 1984 that includes convictions for holding a couple at knifepoint, attacking two men on a golf course and attempting to strangle a shop owner with a telephone cord. While in prison for the golf-course attack, he and other inmates "took over" the prison, holding a group of Chinese inmates hostage, according to court filings.

There are 50 inmates on federal death row in 22 states, according to the Death Penalty Information Center. The last federal prisoner to be executed was Louis Jones Jr. on March 18, 2003, who was convicted of raping and killing a female soldier stationed at Goodfellow Air Force Base in San Angelo, Texas.