On the morning of July 9, 2012, black smoke billowed into the sky above Upperville, Virginia, as a small cabin fire engulfed it in flames.

Firefighters who came to the scene were shocked when they saw the woman’s body in the bedroom. What was even more shocking was that, according to the authorities, the woman died not in the fire, but as a result of a gunshot wound.

The murder of the woman in the shed, 48-year-old Sarah Libbey Greenhalgh, shook the usually quiet town in the middle of the horse estate and her colleagues. Winchester Star, where he works as a reporter and his family.

Greenhalgh’s mysterious murder is featured in the second episode of the season premiere. People Magazine Investigates On Monday, October 28th.

It airs at 10/9c on Investigation Discovery/ID and the titled episode airs on Max. “A Story to Die For” details what happened in the months and years before the talented reporter and photographer was found dead and as police tried to find out who had taken his life.

Greenhalgh’s mother, 95-year-old Sara Lee Greenhalgh, was in disbelief when she learned her daughter had been killed.

“It’s almost impossible to visualize that word,” he says in the episode. “I can’t imagine Sarah being killed. Who does this?

The Fauquier County Sheriff’s Office searched for clues as to who might have wanted Sarah dead.

“One of the biggest breaks in this case came from Sarah herself,” PEOPLE senior writer KC Baker says in an exclusive clip from the season premiere.

“This came in the form of a Facebook post he wrote hours before his death,” Baker says.

The department includes retired Fauquier County Sheriff’s Office Sgt. James Hartman, who is also the department’s public information officer, said Greenhalgh last posted on social media around 11 p.m. the night before he was found dead around 8 a.m. Monday.

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“Sunday night through Monday morning was the big question narrowing down the time frame to determine when this murder was going to happen,” Hartman says.

Greenhalgh’s former reporter friend Melissa Boughton said the Facebook post from the episode was “pretty cryptic.”

“I will sleep with the window wide open. “Now if the crazy boy leaves me alone… I’ll get some much-needed rest because tomorrow is Monday and I have a lot of work to do.”

“As far as we know, this post was the last thing Sarah wrote,” Boughton says.

Hartman adds: “This social media post was very revealing. It was very worrying. Frankly, we wanted to know who the crazy kid was.

That “kid” turned out to be auto body worker John Kearns, then 50, who had been dating Greenhalgh before her death and was seen arguing with him the night before, police said.

An affidavit filed by the Fauquier County Sheriff’s Office named the man as a suspect after observing “significant injuries” to his fists that he said resulted from his martial arts training. The affidavit alleges Kearns deleted email messages to and from Greenhalgh.

However, the affidavit states that no evidence of arson or the “violent struggle” Greenhalgh was involved in before his tragic death was found on his person or in his Jeep.

Kearns, 62, of Virginia, was never charged. He declined to comment to PEOPLE.

People Magazine Investigates: A Story to Die For, It will air on Monday, October 28th at 10/9c on Investigation Discovery/ID and will stream on Max. The episode follows the season premiere People Magazine InvestigatesAiring at 9/8c is the episode titled “The Boogeyman,” which covers the murder of Florida girl Jessica Lunsford.