True-crime author Michael Arntfield talks about homicide detective Pat Postiglione, who headed up Nashville's cold-case Murder Squad and solved dozens of unsolved murders, and how the country-music mecca became a murder hub.

On September 29, 1982, and in the few days that followed, seven people in the Chicago area died in Tylenol-related poisonings. The capsules were all laced with cyanide. The killer or killers have never been found.

With the national homicide-clearance rate below 60 percent, the odds are good that eventually a detective—even an excellent one—will run into a dead end: The case that goes cold, that leaves a family grieving without justice and a detective grasping for answers, even after retirement.

Move over fingerprints—an exciting new field of forensics has emerged: DNA phenotyping, where investigators interpret DNA left behind at a crime scene to make predictions about what the perpetrator might look like. We spoke with Ellen Greytak, a bioinformatics expert, to learn more about the use and limitations of this new science.

In 1991, four teenage girls were brutally murdered in a yogurt shop in Austin, Texas. The killers have never been caught and the crime has never been solved.

Why do so many killers—Jeffrey Dahmer, Ted Bundy and David Berkowitz to name a few—abuse animals before targeting people? An expert provides insights on how the two behaviors are linked.

Tommy Ray, a special agent with the Florida Department of Law Enforcement, came up with an idea that would revolutionize cold-case homicide investigations: making a game out of it.

The year 2017 was an explosive one on the crime-news front. But for the families of some long-ago crime victims, the past 12 months were especially memorable since their loved ones’ cases—some unsolved for decades—took dramatic new steps toward being solved

Read an excerpt from Michael Arntfield's true-crime book 'Mad City: The True Story of the Campus Murders America Forgot,' about the 1968 campus murder of University of Wisconsin-Madison student Christine Rothschild and her best friend's fight to find the killer.

Melting ice that exposed the buried bodies of missing people was one offbeat way a cold case was reopened.