Article continues below advertisementA prisoner who allegedly murdered predator Lostprophets singer Ian Watkins expressed bizarre behavior following the attack, jurors heard. The disgraced rocker was fatally stabbed last October in his cell at a high-security prison in Wakefield, England, where he was serving a 29-year sentence for child sexual offenses.Rico Gedel, 25, is accused of killing Watkins, and is currently standing trial. A court heard statements from prison officers who described him as "smug" and "smirking" after the stabbing.