An update on the 1993 Tricia Pacaccio murder investigation near Chicago, as well as two other slayings and a brutal attack near Los Angeles. The crimes were allegedly committed by Michael Gargiulo, who knew or lived near all four victims.

When Gilles Tetreault arranged to meet a woman he met on an online dating site, he had no idea of the horror that would unfold. Tetreault says he came face-to-face with a madman who had set a trap to kill him. Tetreault was attacked and barely escaped with his life. Johnny Altinger answered a similar online dating ad and disappeared without a trace. Was there really a crime, or was this an elaborate setup for a screenplay for murder? Troy Roberts reports.

A complex case of kidnapping and extortion unfolds in the April 2008 vanishing of the son of a millionaire aviation-business owner. Peter Van Sant reports.

Can a Hollywood movie help solve the most notorious killing spree in Texas? Erin Moriarty reports.

Maureen Maher’s report, “Soccer Moms Confidential,” uncovers the story behind the P.I. Moms, and investigates the man that started it all, Chris Butler. It’s a story allegedly fueled by fame, money, drugs and corruption. Interviews with key players, including the reporter who broke the story and the whistleblower who helped the DOJ bring Butler down, paint a disturbing portrait of an aggressive promoter, an alleged master manipulator. In a special appearance, Dr. Phil tells 48 HOURS what motivates a con man and how easily people are drawn in.

A decorated soldier who was medievac-ed from Iraq and later diagnosed with traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) remembers little of the beating that he gave his 19-year-old girlfriend who died from his hands.

In a small Southern town, an extramarital affair turns into a fatal family affair. Susan Spencer reports.

An update on the case of Anthony Graves, who spent 18 years in a Texas prison for murders he did not commit.

The 1998 death of Ronda Reynolds in Toledo, Wash., is investigated to determine whether it was a suicide or a murder. Author Ann Rule, who wrote a book ("In the Still of the Night") on the case, is interviewed.

A 25-year marriage comes to a violent end. Now, a jury must to decide -- did a wife have the right to kill? Richard Schlesinger reports.

The story of Jamie Laiaddee, a woman who vanished from her home in March of 2010, and how her live-in boyfriend told everyone that she moved to Denver for a new job, but detectives would soon discover that the boyfriend was a con man. Erin Moriarty reports.

A cold case turns white hot as police finally charge one of their own in a 1986 murder case. Maureen Maher has an update.

The 2009 death of boxer Arturo Gatti is investigated to determine whether he committed suicide or was murdered.

Was a teenage girl involved in stabbing her own mother to death... and was it all over a boy? Forbidden young love ends with a mother's violent murder. Richard Schlesinger reports.

When an American goes missing from his sailboat in the Caribbean, his nephew follows the trail with the help of a journalist-turned-manhunter. Peter Van Sant reports.

A Cajun millionaire turned English gentleman becomes a suspect in a murder investigation.

A major break in the Long Island Serial Killer case. The 18-month search for a missing New Jersey woman finally came to an end this week when police on Long Island, New York, announced the discovery remains believed to be 23-year-old Shannan Gilbert. On Saturday, Dec. 17, 2011, the remains were positively identified as Gilbert. As "48 Hours Mystery" correspondent Erin Moriarty reports, the search for Gilbert uncovered a greater mystery. Erin Moriarty has the latest developments.

In April 2010, former reality television producer Bruce Beresford-Redman, his wife, Monica, and their two young children traveled to Cancun, Mexico for a family vacation. On April 8, Monica’s naked, beaten body was discovered in a sewer on the property of the Moon Palace Resort where the family was staying. The vacation was an attempt to save their troubled marriage. The Emmy-nominated producer became a prime suspect in the murder of his wife. Troy Roberts reports.

After a murder rocks the Austin, Texas, music scene, a call to police from an angry wife blows the 26-year-old cold case wide open. Tracy Smith reports.

The 2007 shooting death of Jocelyn Earnest, who was found in her Virginia home with a gun and a suicide note, is investigated. Her husband, Wesley, an assistant high-school principal, is a chief suspect in the case.

An update on the 1994 murder of millionaire William McLaughlin in his Newport Beach, Cal., home. Former NFL linebacker Eric Naposki was convicted of the crime, but he claims he is innocent and speaks about the case.

Following the acquittal of Amanda Knox this week, "48 Hours Mystery" will broadcast "Amanda Knox: The Untold Story". 48 Hours reveals Knox's personal accounts of cruel manipulation and sexual intimidation while in prison. Plus, never-before-seen video diaries from Amanda's best friend, Madison Paxton, collected over 10 months. Paxton moved to Italy to support Amanda and help fight for her freedom.

An investigation into the 2009 murders of the wife and two sons of a security chief for Joyce Meyer Ministries.

Professional poker player Ernie Scherer III is the chief suspect in the 2008 murders of his parents, Ernest Scherer Jr. and Charlene Abendroth, in their Pleasanton, Cal., home.

The dramatic conclusion: Two years after retiring, did world championship boxer Arturo Gatti kill himself or was he murdered? Erin Moriarty has the official findings and the answer to who gets his millions.