"Astonishingly, the events of Aug. 31 and Sept. 1 did not temper the defendant's dangerous, arguably aggressive and out-of-control behavior," Assistant District Attorney Mark J. Conte wrote in his memorandum to the judge.
The defense maintains that O'Neill, 18, has himself been victimized by Sheridan's death, becoming reclusive and despondent - an ideal candidate for treatment in the juvenile system.
"He just feels very, very isolated from everyone," forensic psychologist Bruce Mapes testified, adding that O'Neill has described a "repetitive dream where he's sinking in wet sand or mud."
At stake is the potential punishment: supervision under the juvenile system that would end when O'Neill turns 21 in less than three years vs. a maximum five-year penalty for manslaughter and a 20-year maximum for aggravated assault.
Chester County Court Judge Thomas G. Gavin is expected to decide the issue as early as this week. He will rule based, in part, on five days of testimony by a succession of mostly teenage witnesses who described unsettling activities that preceded and followed the death of Sheridan, 18, of West Chester.
Mike Puliti, who said he was friends with Sheridan and O'Neill, testified that O'Neill brandished a gun at him about 14 hours before shooting Sheridan.
Puliti said O'Neill and some friends arrived at Puliti's house about noon on Aug. 31 so Puliti could cut O'Neill's hair. Puliti said the unloaded gun belonged to another friend, Colin Higgins, and was displayed as a "joke."
