Modern cold-case detectives have plenty of high-tech tools at their disposal. But their hard work may not only expose a killer; it can sometimes reveal missteps and missed opportunities in the original investigation.

A hard-working single mom is murdered in a Michigan town where violent crime rates are nearly four times the national average. And while a TV celebrity leads a major media campaign, the search is on for a mysterious man known only as ‘B’.

The crime scene in Las Vegas has evolved at a rapid rate in the last 50 years, and detectives have had to change their strategies as well.

Prosecuting Attorney, Greg Jacobs, explains why the Polly Klaas murder case was so unique to him.

When a work crew uncovers a woman’s skull on a stretch of Florida highway, investigators try to determine who she is and find her killer. But it will take a bizarre discovery over a thousand miles away before the grizzly truth is finally revealed.

In 1999, 19-year-old journalism student, Brook Baker, is murdered in her apartment sending shock waves through the once peaceful Vincennes, Indiana, and setting in motion a desperate police investigation.

In 2004, local authorities call in blood stain pattern analyst, Stuart James, when Cathy Lamb is found dead in Palm Beach County, Florida. What does the blood in her house tell him about the murder?

The body of Marilyn Habian, a popular teacher with a passion for dance, is found in the basement of her home. There are no witnesses or signs of forced entry, but evidence from the crime scene suggests Habian caught the perpetrator in the act before she was shot in the heart.

On her last day as a high school freshman, 14-year-old Jessica McHenry vanishes. The victim of a shocking and brutal murder, her badly burned body is found in a field just outside of town. While her sleepy community deals with the aftermath, police hunt for a monster.

14-year-old Gloria Pointer is snatched off the street, assaulted and murdered on her way to school. Detectives work the case day and night, but a lucky break nearly 30 years later will put the culprit behind bars. Now her mother, Yvonne Pointer is dedicated to serving others.

31-year-old bartender Deborah Fielding’s body is dumped in an Orlando park. And as detectives connect the dots, a spate of seemingly random beatings, carjackings, and murders tells the story of a one-man crime spree.

Kimberly Dunkin's body is found with a single gunshot to the head. At first, investigators suspect she was the victim of a gang war. It will take 15 years, a deck of playing cards, and a lucky break before the case finally begins to unravel.

While building their dream home, Matthew Monahon discovers his pregnant wife Kelsey hogtied on the floor and clinging to life. When she dies days later, a $300,000 life insurance policy casts him as the number one suspect.

18-year-old Debra Ann Dill had just quit high school to get married to a local police officer. Dill leaves one night for a date with her fiancé, but the next morning, her body is discovered next to her car. Twelve state police investigators are assigned to the case, but after interviewing hundreds of people, the case goes cold. That is, until 15 years later when a phone call from a Connecticut prison changed everything.

Police in Hillsborough County, Florida investigate the murders of three young women. They describe what it's like for homicide detectives to work a case with such an emotional impact on the victims' family.

Police often wait 48 hours to start looking for missing adults. When Carla Larson goes missing investigators jump on the case right away. Lead Detective John Linnert explains why.