Nicodemo is charged with murder and related offenses for his involvement in the death DiPietro.
DiPietro was gunned down outside his South Philadelphia home Wednesday afternoon.
Witnesses say the gunman was driving a black SUV and they got the tag number. It was traced to the 41-year-old Nicodemo.
Police sources say he has not been cooperating. But now ballistic tests have come back and, according to our sources, they reveal a match between bullets found in DiPietro's clothing and a gun found in Nicodemo's car.
Meanwhile, the victim's family is quite distraught, and outraged over any suggestions that he might have had something to do with the mob.
"I'm the one who should have died first. Not my boy. That boy killed my son for nothing," said DiPietro's mother, Catherine Viola.
DiPietro doted on his mother and his two sons. They say that was his family, not La Cosa Nostra.
"He was a single father," said DiPietro's sister, Linda Shattuck. "Went to work, raised his boys. Did whatever he had to do to make life convenient for them, gave them a good education. Make sure they went to work and made money. And then, this."
DiPietro's family says he never associated with Nicodemo or anyone else in the mob.
"He might have known these people. He might have gone to school with some of them. But he didn't associate with them. Never did," said DiPietro's brother-in-law, Vincent Shattuck.
DiPietro was jailed on drug charges in 1997 and got out six years later. His family says he had turned his life around. He was hoping to get a college degree and marry his girlfriend.
"You killed one person. They were in pain for ten minutes. And look what you're going to do to a family for the rest of our lives," said his fianc? Alisa Lord.
DiPietro's family can't imagine why he was targeted. They say he was a happy man who lived simply and treasured his family.
"It's not fair to kill my boy. They killed me, too. I want to die too, now. I don't want to be here," said his mother.
They remain a family in agony, looking for answers.
Police say they have uncovered no motive for the murder.