When two handcuffed inmates at one of Nevada's toughest prisons brawled in a hallway, one ended up dead from several shotgun blasts. The other was declared guilty of murder, even though he never touched a gun.

Prison officials acknowledged the death in November with only a short statement, and for months they never mentioned that a weapon was involved or that it had been fired by a trainee guard.

Since then, the mystery of the shooting near the showers in a segregation unit at High Desert State Prison has only deepened.

Now attorneys for both inmates are accusing prison guards of instigating the fight to set up a gladiator-style contest and then trying to cover it up by blaming the surviving prisoner.

Prison officials have been slow to release details.