Batzig, 18, Domenic Coia, 19, and his brother Nicholas Coia, 18, are standing trial together as adults, charged with first-degree murder in the May 2003 killing. If convicted, Domenic Coia could face the death penalty. His brother and Batzig face life in prison without parole.
Yesterday, lawyers for each of the three acknowledged the teens played a role in Sweeney's death. But they suggested that the drug-addicted defendants were incapable of having a fully formed intent to kill.
Each may rely on expert psychiatric testimony in an attempt to determine the teenagers' states of mind at the time Sweeney was slain, and to persuade jurors that their clients are guilty of third-degree murder instead of first-degree.
The attorneys also suggested that the prosecution's star eyewitness - the girl who lured Sweeney to the vacant lot with the promise of sex - was the manipulating force behind the crime.
That witness, Justina Morley, now 16, may take the witness stand today in the trial before Common Pleas Court Judge Renee Cardwell Hughes.
"Evil comes in many forms," Assistant District Attorney Jude Conroy told jurors in his opening statement. "And Justina Morley was 15 years old at the time, [a student] at a parochial school in Fishtown.
"You will not like her - nor should you like her," Conroy told the jury. "She wears this [crime] as a badge of honor."
Sweeney had never had a girlfriend, and Morley's job in the crime was to be the "bait," Conroy explained, so the others could rob and kill Sweeney for the $500 he earned working construction with his father.
Morley pleaded guilty last year to third-degree murder. In exchange for her plea and testimony against the others, she will received a 17 1/2- to 35-year prison sentence.
Assistant Defender Karl Schwartz told jurors that Morley was "at the vortex, at the center of this craziness. . . . [She] very much influenced Eddie Batzig, who was as lovesick toward her as anyone.