Part 2: Four young women attacked, only one survivor. "48 Hours" correspondent Maureen Maher has been on the trail of serial killer Michael Gargiulo for more than a decade. How "48 Hours" helped crack one of the cases.

The parents of Brooke Skylar Richardson speak out -- the real story behind the international headlines in the case of an alleged unthinkable crime. "48 Hours" correspondent Erin Moriarty investigates.

A mom vanishes and now her fiancé is in jail awaiting trial for her murder. His former rodeo queen girlfriend says she knows what really happened. CBS News correspondent Nikki Battiste reports.

Abducted by masked gunmen and buried alive in a truck trailer, survivors relive the horrifying time they spent underground and their journey to escape.

An Ohio mother is brutally murdered. A detective pursues the wrong suspects, while the real killer walked free. It would take a dedicated sheriff to find a real suspect. Were there other victims? CBS News' Jim Axelrod reports.

The wife of a NYC businessman is suspected of murdering him with help from her brother -- why would she want him dead and why did it take more than two decades to crack the case? "48 Hours" correspondent Richard Schlesinger reports.

A young woman vanished after a night out in Milwaukee in October 2013. Did a meeting set up on a dating app lead to the disappearance or was it someone she knew? "48 Hours" correspondent Peter Van Sant reports.

A brutal murder and police have DNA evidence — could a discarded cigarette lead investigators to a possible killer and close a case two decades later? CBS News correspondent Anne-Marie Green reports.

A woman repeatedly threatened to kill her ex. She enlisted her father to help make good on her promise. Why couldn’t anyone stop her? "48 Hours" correspondent Peter Van Sant reports.

An inside look at the startling evidence that helped convict against Colorado man Patrick Frazee for the murder of his fianceé. CBS News correspondent Nikki Battiste reports.

How a bakery worker’s secret plan to recover DNA from a discarded Coke can helped investigators solve the cold case of a college student murdered over Thanksgiving weekend. "48 Hours" correspondent Peter Van Sant reports.

A California police officer shot dead in his home -- his ex-wife admits she pulled the trigger. Did a photo posted on social media lead to the officer’s death? 48 Hours" correspondent Erin Moriarty reports.

Hostages chillingly reveal the terrifying three hours they spent held captive by a gunman inside a California supermarket. CBS News' Jim Axelrod reports.

Hear for the first time from the woman at the center of a case prosecutors said was all about ”sex, lies, money and murder.” "48 Hours" correspondent Peter Van Sant reports.

A survivor deals with the trauma after her stepbrother is convicted of killing her family in order to go to the prom. CBS News' Jim Axelrod reports.

A woman accused of setting her house on fire and then intentionally running over her husband as he escaped the flames speaks out for the first time. "48 Hours" correspondent Erin Moriarty reports.

A young woman claims she was attacked by an ex-boyfriend who carved the word boy into her arm. But the crime scene tells a different story. CBS News correspondent Jamie Yuccas reports.

Did a Florida man hire a look-a-like to kill his wife? A GPS leads police right to the hitman’s door. "48 Hours" correspondent Erin Moriarty reports.

An investigation into the death of a Hollywood therapist. Did the system do enough to protect her from alleged killer Gareth Pursehouse? Her former fiancé Drew Carey calls for updated laws. "48 Hours" Erin Moriarty reports.

A former beauty queen vanishes. One man said he had answers. Why didn’t anyone listen?. "48 Hours" correspondent Peter Van Sant reports.

A rare look inside a murder case where virtually everything from the first moments of the investigation through the verdict are captured on camera. Correspondent Richard Schlesinger reports.

A story of tragedy and triumph -- the murder of a young woman and how her killer's heart saves the life of a dying woman.

A man on death row says his blood was planted at the crime scene. Will an empty vial help his case?

Did Lizzie Borden really hack her parents to death? A surprising answer and an inside look at the haunting crime scene. Erin Moriarty reports.

When police are called to an upscale Gainesville, Fla., home to a find a couple stabbed and bleeding, the husband says an intruder attacked them; when the wife regains consciousness, she has a very different story.

Notorious serial killer Ted Bundy targeted three young Florida women in one of his final attacks. They survived and share their terrifying ordeal and long road to recovery. CBS News correspondent Tracy Smith reports.

A Florida man remains in prison two years after his 1990 murder conviction -- which his lawyers call a "racial hoax" -- is overturned by a federal judge.

A college student goes missing -- the “Find My Friends” app leads to her body as her suspected killer flees the country. Will he get away with murder? CBS News contributor Maria Elena Salinas reports.

Detectives believe a 13-year-old girl who vanished from her California home in 1981 was murdered; more than 20 years after the disappearance, a traffic stop in Arizona turns up a woman claiming to be the missing girl.

The FBI believes skulls drawn in blood are the number of victims murdered by a prolific serial killer. Inside the FBI's search to identify them. "48 Hours" correspondent Peter Van Sant reports.

Two children vanish and an Idaho mother won’t say where they are. In their first network TV interview, her mother and sister say she’d never harm her children. So where are the kids? CBS News correspondent Jonathan Vigliotti reports.

After 40 years, police arrest the man they think committed at least 50 rapes and 12 murders.