Man charged with murder in cold case featured on "48 Hours Mystery"

Alleged serial killer Michael Gargiulo charged with first-degree murder in 1993 stabbing death of Tricia Pacaccio

CHICAGO - Following a "48 Hours Mystery" report that brought forward new witnesses, Cook County prosecutors have charged a man in the 1993 stabbing death of Tricia Pacaccio.

At a news conference Thursday, Cook County State's Attorney Anita Alvarez announced Michael Gargiulo, 35, has been charged with first-degree murder in the death of the Glenview, Ill., 18-year-old.

Officials said two new witness who came forward since the broadcast aired in May were interviewed "at length," leading to the charges being filed in the cold case.

In a press release, the Cook County State's Attorney's Office stated, "In May of 2011, [our] office, as part of efforts in the continuing cold case investigation, participated in a CBS '48 Hours Mystery' television investigative episode which profiled Gargiulo's crimes in California and his potential link to the Pacaccio homicide in Cook County. As a result of the airing of the television program, two new witnesses came forward who had worked with Gargiulo at a bar and grill in Hollywood, California in the late 1990's."

Rick Pacaccio, the father of Tricia, thanked CBS News and "48 Hours Mystery" by phone Thursday, saying, "There is no doubt about it, you guys did good. The informant saw me on the show and couldn't take it anymore, and came forward."

Gargiulo currently faces two murder charges and a rape charge in California.

Read more: "The Boy Next Door"
Photos: The victims
Photos: Gargiulo's L.A arrest

The "48 Hours" broadcast, "The Boy Next Door," featured correspondent Maureen Maher's report on the murder of three women - one in Illinois and two in California - and the search for an alleged serial killer thought to be behind it all.

The murder at the heart of the case was the Aug. 14, 1993, stabbing death of Pacaccio. The 18-year-old had returned home from a night out with friends when she was stabbed to death on her doorstep by an attacker. She was found by her father.

According to the Cook County Sheriff's Office, she had been stabbed 12 times.

Authorities say Gargiulo, who lived near the Pacaccios, was questioned about Tricia's death, but was never charged.

The case went cold until 2001, when authorities in California were investigating the murder of Ashley Ellerin, 22, in Hollywood.

Ellerin was planning to go on a date with actor Ashton Kutcher the night she was murdered. The main suspect in the Ellerin case - Michael Gargiulo - turned out to be a classmate of Tricia Pacaccio's, and a person of interest in her murder. But even as authorities in California and Illinois were investigating the Pacaccio and Ellerin murder cases, two other California women came face to face with a killer - and one survived - providing a crucial piece of evidence.

It was then when authorities linked all of the murders to Gargiulo through DNA.

Photos: Police seek info on woman photographed with Gargiulo

While already in jail charged with attempted murder for an attack in Santa Monica, on Sept. 4, 2008, Gargiulo was indicted on two additional charges - the murders of Ellerin and Maria Bruno.