In December 2020, a team of civilian codebreaker broke one of the unknown killer's messages after 51 years. Are we now closer to finally finding out who he is?

In the 1960s, an unidentified serial killer terrorized London sex workers. The Hammersmith Nude Murders remains one of Britain's most infamous unsolved crimes.

Posthumous DNA testing proved what Roger Keith Coleman repeatedly denied—that the Virginia man raped and murdered his sister-in-law in 1981.

After the Golden State Killer's arrest in 2018, dozens of rape victims learned their assaults weren't isolated incidents but the work of a serial killer. Read how many survivors bonded through mutual trauma.

Shayna Hubers shot and killed her boyfriend, Ryan Poston, claiming it was self-defense. But at the murder scene, there were few indications of a domestic disturbance. Read more about this bizarre case.

Peter Sutcliffe had the makings of a serial killer before he claimed his first victim and continued on a murderous spree that terrorized England for nearly five years.

An episode of 'Killer Cases' focuses on a mysterious triple murder in Pensacola that brought whispers of black magic to the Florida panhandle. 

Florida mom Casey Anthony lied to investigators about the 2008 disappearance of her 2-year-old daughter Caylee Anthony for weeks. We've compiled a list of some of her most questionable statements.

Nearly 20 years ago, retired NYPD detectives started tracking the suspicious drownings of young men across the country after they discovered a graffiti smiley face near at least a dozen locations where they found bodies.

While her husband and daughters were out of state, Dr. Teresa Sievers was murdered. 'This was almost the perfect crime,' says prosecutor Cynthia Ross. 'There was absolutely no trace evidence.'