Mark of a Killer Season 4: Episode Guide & Ratings

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

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.

Police in Hartford, Connecticut 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.

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