From the arrest of a suspect in the Golden State Killer case to a serial killer's confession to the murder of 90 women, 2018 has been a breakthrough year for cold cases.

In November 2018, serial killer Samuel Little, 78, confessed to murdering 90 women. While the number may be astonishing, the duration of Little's homicidal behavior, and the ages at which he committed his crimes, are also noteworthy.

Convicted serial killer Samuel Little recently confessed to 90 more murders. If all of his killings are confirmed, Little, currently age 78, would be the most prolific serial killer in American history. Learn more about Little and his confession.

The United States may have churned out the highest number of serial killers in the world over the years, but it certainly doesn't hold exclusive rights on brutal murders. Learn about some international serial killers and how their respective countries handled their crimes.

Nicknamed 'The Dating Game Killer' after his 1978 appearance on the TV show of the same name while in the middle of a killing spree, Rodney Alcala died on July 24, 2021. Although convicted of seven murders, investigators speculate there are more victims.

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.

Doctors who murder are a rare breed, but perhaps because their entire mission is to do no harm, they are among the most chilling kind of killers. Texas surgeon Dr. Christopher Duntsch is one such physician who violated his oath so profoundly by intentionally botching surgeries that he became known as 'Dr. Death.'

For Jeffrey Dahmer, it was watching certain movies. Dennis Rader, known as the BTK Killer, set the mood by pretending he was a spy. Ted Bundy liked drinking alcohol before some of his slayings. Not every serial killer has a signature routine, but some of them do engage in some sort of ritual or preparation before a killing.

Read an excerpt from Michael Arntfield's true-crime book, 'Monster City,' about serial killer Tom Steeples, a computer store owner who found two of his victims, a newly married couple, at a dive bar's amateur showcase.

Although cannibals have always existed throughout human history as a cure for overpopulation, a means of survival during a famine, or even a way to contend with grief, what's more rare are murderers who kill for sport and then devour their victims. We talk to Dr. Eric Hickey, a forensic psychologist, on why some killers eat their prey.