Two days after Christmas a mass shooting terrorizes a small town. After killing two people and wounding many more the gunman is taken into custody. When police search for answers they uncover the worst family massacre in US history.

Just after Christmas, a young couple is found murdered inside their Florida home. Neighbors can't imagine the couple had been in the area long enough to make a mortal enemy. Police uncover deeply personal details, and soon expose a deadly secret.

A Thanksgiving feast turns into a family's last when a cold blooded killer brutally stabs and dismembers a couple the day after their holiday celebration.

The Ortega family's annual Christmas Eve party is destroyed when a man dressed as Santa, wielding handguns and a homemade flame-thrower opens fire. Detectives are led down a terrifying path that leads them to a sociopath.

Just before New Years, a hockey mom is gunned down at her front door. Later that night, seven more bodies are found in another suburban home. Police discover a shocking connection between the two crimes as they track down the killer.

After a family is found massacred inside their Santa Claus, Georgia home, the hunt for their killer hinges on the eyewitness testimony of the three young surviving daughters.

A deranged shooter attacks a family Thanksgiving dinner, leaving four dead and even more wounded. This horrific crime sets off a massive holiday-season manhunt to catch the killer – before they can strike again.

Dayton, Ohio, is terrorized over the Christmas holiday as a string of brutal shootings have the residents wondering if they could be next.

The holiday season screeches to a halt when six members of the Anderson family are discovered to have been gunned down in their home. Detectives work closely with family friends to track down the shocking murderer.

After a woman and her unborn child are stabbed to death on Halloween by a man wearing a wolf mask, investigators must calm the community and find the killer before he strikes again.

On Christmas Eve in a quiet town, elderly couple Bob and Idella Young are brutally slain at home; a bloody glove found at the crime scene has the killer's DNA, but no one matches the sample.

New Year’s in a tiny town, Joanna and Carl Dutcher ring in the year with their grandson. Days later, they are found violently killed. The hunt for the killer leads police to a sinister group that threatens the entire community.

When a mother and her two daughters fail to show up for Christmas dinner, officers enter their home and discover all three have been shot to death. The search for their killer reveals an unthinkable family nightmare.

Earl and Terry Robertson are found brutally murdered in their home just before Thanksgiving; investigating whether this is a holiday robbery gone terribly wrong, or a crime committed by someone the couple knew and trusted.

Firefighters respond to a house fire and discover three gunshot victims inside; authorities pursue the heavily armed murderer through Christmas.

A mother is brutally shot to death while driving her sons home from a Thanksgiving celebration. When the hunt for her killer leads to an unlikely suspect, investigators soon realize her murder is not as random as it once seemed.

When a young man and woman are found shot execution style in a mall parking lot in the early hours of Christmas Eve, investigators believe a love triangle might have led to these brutal murders. A weeks-long search for the prime suspect uncovers another murder and a devious killer.

A prominent couple is found brutally murdered in their Montgomery, Alabama, home on Thanksgiving night, leading detectives on a cat and mouse chase spanning thousands of miles across multiple states.

After responding to a robbery at a sporting goods store on Christmas Eve, an Irving, Texas police officer is gunned down in cold blood.

A holiday is ruined when a couple is gunned down in their bed during what looks like a brutal home invasion. Police soon discover the true motive for the double homicide - a shocking tale of deception and betrayal.

After a single young mother fails to show up for work on Halloween, her family and friends suspect murder.

An abandoned car filled with blood found in a pond leads investigators on the trail of a missing woman and her teenage daughter, who never showed up to the family's July 4th party; when their remains are found in another pond, everyone in their small town is a suspect.

A couple is found murdered inside their home on Christmas morning. All that's left behind is a single palm print. Investigators work tirelessly to match the print to a suspect, until a letter from prison takes the case on an unexpected course.

A teenage boy discovers a real-life horror scene in his home on Halloween morning; investigators must determine if the triple homicide is a random act of evil or a premeditated slaughter by someone close to the family.

When a young woman goes missing after a July 4th beach party, investigators have few clues to go on until a twist in the case reveals she might be the latest victim of a predator terrorizing the area.