Stab victim's brother now suspects boy next door

Michael Gargiulo stands accused in California of brutally attacking one woman and killing two others. But California law enforcement officials say they believe Gargiulo's first victim -- before the other three -- was Tricia Pacaccio, an 18-year-old from Glenview, Ill., who was stabbed to death in 1993 on the doorstep of her home.

On "The Early Show" Friday, Tricia's brother, Dr. Doug Pacaccio said it now makes sense to him that Gargiulo could be responsible for his sister's murder.

Watch a sneak peek of "48 Hours Mystery" "The Boy Next Door."

He said, "It made sense in hindsight. But at the time, no. I mean, you see the side of this guy. He was a neighborhood kid, grew up, we were all kids together, and he was familiar with the area, familiar with all the families. You just don't look in your own backyard on some of these things because it was such a shock, and the whole episode was such a mystery to everybody in terms of who would want to attack my sister. She was harmless. She had nothing but friends."

He continued, "And when you look in hindsight, you know, it makes sense, because it's such a senseless thing, and it clearly, Michael has (allegedly) done this several times since. So, at the time, it was hard to imagine. But, it seems to make sense now."

Pacaccio said he learned of Gargiulo's alleged involvement in the attacks in California from cold case detectives in 2004. He said they told him they found Gargiulo's DNA at the scene of his sister's murder.

Looking back to conversations, Pacaccio recalled an incident when Gargiulo, he said, asked him if he found out who his sister's killer was, if he would kill him.

Pacaccio said, "I thought it was just one of those things that, a piece of conversation, that he wouldn't have been the first person to ask me that. I think people try to get inside our heads in terms of what's going through our minds, and how we feel about what happened. And my answer was - and I don't remember if my answer was - I would, or that I could. But it was an affirmative answer, for sure. And I didn't know at the time that he was maybe testing me. We thought that he was probably or likely going to confess. And when I told him, sure, I would or could, but I'd have to get in line with probably every other guy in my family, and who was friends with my sister. And I think he took that as a threat, actually."

"Early Show" co-anchor Chris Wragge asked what has apparently stalled the Illinois investigation into Tricia's murder, particularly with the DNA evidence.

Pacaccio said it may be due to politicians trying to save face.

"We've had the hardest time figuring out why this is happening the way it's happening," Pacaccio said. "They have DNA at the scene. He did not have any contact with her, despite the fact that she had contact with all of her classmates that very night on their senior road rally. So, why they haven't pursued this, to me, being on the inside, it seems somewhat political."

Pacaccio continued, "They would maybe have to admit that some mistakes were made and reconcile those mistakes, and at times I think, when political careers are involved, it's easier to ignore something that isn't close to them than to actually do the right thing and pursue it."

For the full story, watch "The Boy Next Door" on CBS' "48 Hours Mystery" Saturday night at 10/9c.