Serial killers like Ted Bundy and John Wayne Gacy led reigns of terror with striking frequency. Several factors could explain the glut.

And there is no shortage of experts offering opinions on the various characteristics of serial killers--their personalities, motivations, methods of operation, and crime-scene behaviors.

The “Parent Trap” star portrays Keith Hunter Jesperson in “Happy Face,” which begins streaming Thursday on Paramount+.

In addition to this, within the true crime media world, serial killers seem to be a topic people are most morbidly fascinated with. From May 1918 until October 1919, the "Axeman of New Orleans ...