Watch Mark of a Killer

A serial sniper terrorizes the entire D.C. metro area by discreetly targeting random victims out in public and in plain sight.

Police in Hartford, Conn., investigate a string of ruthless killings in the Asylum Hill area committed by a killer with a devastating mark that leaves his victims nearly unrecognizable.

When multiple victims' bodies are dumped around Louisiana's bayou area, a task force is formed to catch a killer who police believe may have strangled over 20 men.

Investigators in East Baton Rouge, La., hunt for a serial murderer who carefully carves up and cuts the bodies of his victims after death.

Chaos descends on Phoenix as two serial killers compete for the media's attention and the bodies pile up faster than the police can investigate.

El Paso investigators race to track down a ruthless killer who is burying his victims in shallow desert graves, dead or alive.

A Houston killer taunts the media and authorities as he uses homemade ligatures to murder his victims.

A cold-blooded killer conceals his victims' bodies with trash, discarding them like garbage in the back alleyways of Los Angeles.

A killer crisscrosses the Midwest leaving a string of victims along the interstate, but when he realizes investigators are hot on his trail the murderer suddenly changes his mark.

Chicago detectives believe a serial killer is using the classified ads to lure and murder his victims. The investigation is set ablaze when flames obliterate evidence, until police make a shocking discovery.

Chicago police are investigating the murders of several women, whose bodies are discovered in abandoned buildings barefoot. Evidence indicates there is one offender, now police need to locate him.

A series of women in the Seattle area are found brutally murdered, their bodies posed. Police realize they may have a killer stalking the area nightclub scene, one who is able to charm his victims into submission.

After multiple men are discovered brutally murdered, investigators determine that each victim was last seen with a handsome stranger they met in a bar. Police ask the public for help in tracking down a dangerous drifter before he kills again.

A killer is murdering and mutilating young women along the Route 40 corridor in Delaware. But when investigators set up an undercover operation, the hunter soon becomes the hunted.