When a chilling 911 call came in at 11:34 AM on Christmas Day in 2011, it immediately set off alarm bells for the Grapevine, Texas police.

The voice on the other end was faint, muttering what sounded like “Help me, help me” before the line went dead. Concerned for the welfare of whoever was inside, officers were dispatched to the home where the call originated.

When officers arrived at the apartment, they were met with an eerie silence after their knocking yielded no response.

When they forced the door open, they were unprepared for the horrifying scene awaiting them.

Inside the living room, surrounded by Christmas presents and torn wrapping paper, lay the bodies of seven people, all shot to death.

The victims, all family members, ranged in age from teenagers to seniors. This was no random act of violence — it was a massacre.

But who were these victims? And what kind of darkness could drive someone to commit such an unspeakable act on Christmas Day?