Mark Branch: The Grocery Clerk Who Thought He Was Jason Voorhees

October 24th, 1988. Greenfield, Massachusetts. A 19-year-old grocery clerk puts on a hockey mask, grabs a knife, and walks to his victim's house. He's about to make his favorite horror movie a reality. The victim? An 18-year-old college student who made one fatal mistake: she tried to understand him.

Sharon Gregory Murder: Psychology Student Killed in Greenfield Massachusetts 1988

Sharon Gregory was doing everything right. Fall semester 1988 at Greenfield Community College, and the 18-year-old psychology major was keeping up with her coursework, hanging out with her identical twin sister Cheryl, and working on what she probably thought was a fascinating assignment. She'd chosen to do a psychological evaluation of someone she knew around town. Someone who made her twin sister uncomfortable. Someone named Mark Branch.

Mark Branch was a 19-year-old grocery clerk who was obsessed with horror movies, specifically the violence within these movies. But calling it an obsession doesn't really capture what was going on. The clerk at Video Expo 1 in Greenfield would later say that Mark rented strictly gore, period. The gorier, the better. We're not talking about someone who liked scary movies. We're talking about someone who studied them like other people study textbooks.

Mark Branch: The Friday the 13th Obsessed Killer

Mark had a special interest with the Friday the 13th movie series, a franchise of slasher films surrounding character Jason Voorhees who wore a hockey mask and stalked his victims. And when police would eventually search his apartment, what they found was beyond disturbing. They reportedly recovered 75 slasher films, 64 killer-related books, 12 hockey masks, 3 knives, and a machete. Twelve hockey masks. This was less of a fan collection… more like a blueprint.

Throughout his earlier teenage years, Mark had terrified and repulsed his female classmates. So when Sharon Gregory decided to do a psychological profile on him, whether for a class assignment or personal interest, she was stepping into dangerous territory. And Mark knew about it. He knew she was analyzing him, picking apart his brain, writing down her conclusions about what made him tick. 

Greenfield Police Chief David McCarthy would later reveal the motive. As far as he was concerned, the bottom line motive was that Sharon Gregory had in her possession a psychological profile of Mark Branch and that profile was wanted badly by Mark Branch. He didn't like being studied. He didn't like being figured out. And he wanted that profile back.

October 24 1988 Greenfield Murder: What Happened to Sharon Gregory

On October 24th, 1988, Mark put on a pair of black boots and a hockey mask to resemble Jason and started heading over to Sharon's apartment. It was a Monday afternoon. Halloween was just days away. The town would soon be preparing for parades and trick-or-treating. But Mark Branch had his own celebration planned.

What exactly happened inside Sharon's apartment, we'll never fully know. Sharon's twin sister Cheryl found her body in the upstairs bathroom. The scene was horrific. Sharon had been stabbed multiple times in her head, neck and chest. This wasn't a quick kill. This was fury. This was someone acting out every violent scene they'd memorized from dozens of slasher films.

Cheryl was able to tell police that they needed to look into someone Sharon knew named Mark, who she said had made her uncomfortable by the way he looked at her. She knew immediately. The twins had probably talked about him. About how weird he was. About how he made her feel. And now her sister was gone.

Halloween 1988 Canceled: Greenfield Massachusetts Manhunt for Mark Branch

A neighbor verified that someone fitting Mark's description had been at the home for a few minutes that night. Within days, tips started flooding in. People around Greenfield knew about Mark. They knew about his obsession. They knew he'd talked about wanting to kill.

Police searched his apartment and they found a set up, almost a shrine, dedicated to gore and horror with multiple items relating to Jason Voorhees. But Mark was gone. Police received another tip from someone who reported that they believed they had found Mark's car, abandoned 13 miles outside of Greenfield in nearby Buckland. The car had blood on the front seat and front console, sparking a massive manhunt.

Here's where this story goes from tragedy to community nightmare. After several days when Mark still wasn't found, and with Halloween quickly approaching, the rest of the town was on edge and terrified. Think about that. You've got a guy who dressed up as Jason Voorhees running around somewhere, and Halloween is in less than a week.

Media coverage only fueled the fear in the town, with the parade and annual events downtown being canceled and trick-or-treating moved to daylight hours at the insistence of concerned parents. Parents who had grown up watching Friday the 13th movies were now living in one. Halloween came and went without incident, but Mark was still out there.

Mark Branch Body Found: November 1988 Discovery in Buckland Massachusetts

Over a month after Sharon's murder, on November 28th, police received a tip from a local hunter who was hunting deer during the first week of deer season. Deer season had opened on Monday, November 21st. Hunters were back in the woods. And one of them found something no one expected.

He had found Mark's body in the woods hanging from his belt and shoelaces from a pine tree. His death was tentatively ruled a suicide, and the medical examiner determined that his death had taken place shortly after he murdered Sharon.

So here's what happened. Mark Branch killed Sharon Gregory on October 24th, fled to the woods in nearby Buckland where his car was found, and took his own life probably within days of the murder. But his body wasn't discovered for over a month. The town of Greenfield lived in terror for five weeks, canceling Halloween celebrations, keeping kids inside, reporting sightings of Mark all over New England. And the whole time, he was already dead, hanging from a tree 13 miles away.

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Sharon Gregory Psychological Profile: The Document Never Found

The psychological profile that Sharon wrote on Mark was never found. Did he destroy it before he died? Did he have it with him in the woods? We don't know. McCarthy said Branch's particular interest in Jason was part of the motive for the stabbing, explaining that police had confirmed Mark had a mental illness of some kind that was confirmed by his parents.

McCarthy later elaborated on what he believed drove Mark to kill. He was so entrenched with Jason that he had to have the final chapter in his own feelings. He wanted to know what it felt like to live out the part of Jason. This wasn't about the profile alone. This was about a young man who had become so detached from reality that he believed he could become the character he'd watched kill dozens of people on screen.

Horror Movies and Violence: The Mark Branch Case Debate

The media did not let up about the angle of Mark's horror movie obsession and the Friday the 13th aspect. This case became ammunition for every parent, politician, and activist who believed horror movies were corrupting youth. And honestly, it's hard not to see why they made that connection. A guy who collected 12 hockey masks and 75 slasher films puts on a Jason costume and stabs someone to death. The correlation is right there.

But here's the thing. Millions of people watched Friday the 13th movies in the 1980s. Millions of teenagers rented those same films from video stores. They didn't become killers. Mark Branch had something else going on. He had documented mental illness. He'd been under psychiatric care for years. One report mentioned he'd sought treatment at a Boston psychiatric hospital after leaving a private school six weeks into the school year back in 1984.

The movies didn't create Mark Branch. But they gave him a template. They gave him a costume. They gave him a fantasy to step into when his reality became unbearable. And Sharon Gregory, who was trying to understand him through her psychology studies, became the victim of that fantasy.

Sharon Gregory Family: Twin Sister Cheryl and the Aftermath

When told of Mark's death, Sharon's father Edward said they were glad it was over. It was time to forget and carry on as best they can. But how do you carry on after something like this? Cheryl Gregory found her identical twin sister murdered in their bathroom. She'd have to live with that image forever. Their parents lost a daughter to senseless violence right before Halloween, and then had to wait over a month while the town lived in fear before learning the killer had been dead almost the entire time.

There was no trial. No conviction. No moment in court where the Gregory family could face Mark Branch and get answers. Local newspapers even petitioned the courts to release documents about the murder, evidence taken from Mark's home and the crime scene, but Mark's family fought to keep those details private. So we're left with fragments. With police statements and news reports and a community that still talks about the Halloween that got canceled.

Sharon Gregory was 18 years old. She was smart, studying psychology, probably hoping to help people understand mental illness someday. Instead, she became a case study herself. A cautionary tale about getting too close to darkness while trying to shine a light on it.