Martinson described herself online as a “horror fanatic” and went by the pseudonym “Vampchick,” according to People.

“I clean the dry blood off my tools from a previous session,” she wrote in the chilling March 2015 post, called “Unworthy.”

AD

“The last body has been disposed of just hours before, yet I have not been satisfied with the pain, agony and blood.

“I bend down as they start to wake.

AD

“‘Welcome to hell.’ I whisper in her ear. ‘Never again will you see the light of day.'”

Five days later, Martinson’s parents were found dead at their home in the tiny town of Piehl, in northern Wisconsin.

Investigators immediately turned their attention to Martinson, who had fled to Indiana with her boyfriend.

She was arrested and charged after police said she shot and killed her stepfather and then fatally stabbed her mother more than 30 times.

Now 18, Martinson pleaded guilty last week to second-degree homicide.

On March 7, 2015, one day after her 17th birthday, Martinson got into an argument with her parents, she later told police.

AD

Her younger sister told authorities that Martinson’s mother and stepfather had discovered that the teen had a 22-year-old boyfriend and sent him a message on Facebook telling him to stay away from their daughter, according to court documents.

AD

“As her parents,” her parents wrote, “we can press charges.”

They took away Martinson’s keys and cellphone, according to the documents, and forbid her from seeing him again.

The three fought. Martinson left home on foot and her stepfather brought her back.

Then, she went to her room.

Martinson told police that she grabbed “one of the many loaded shotguns in the house” and prepared to commit suicide, according to the documents.

AD

But when her stepfather started “loudly banging” on her bedroom door, she said she considered killing him instead.

Two gunshots rang out.

Martinson shot 37-year-old Thomas Ayers first in the neck, then took aim at his head, authorities said.

She told police the second shot was “to ensure that he was dead and could not hurt her,” according to court records.

She said she turned to her mother for comfort, but her mother ran to Ayers, yelling at her daughter for what she had done.

AD

Martinson told police that her mother, 40-year-old Jennifer Ayers, grabbed a knife and came toward her, according to court records. The teen wrestled the weapon from her mother, then stabbed her “with considerable force” over and over and over.

AD

“She was basically a good kid, a very decent girl, until this happened,” her friend, Jon Rasmussen, told the Milwaukee Journal Sentinel last year.

Accounts from Martinson and professionals who interviewed her after the incident portray a teenage girl who, after years of alleged abuse, suffered severe depression and post-traumatic stress disorder.

Her online presence, it seems, revealed the darker side.

Martinson had put pictures on Pinterest that she said came from “the dark, haunted woods of Wisconsin,” according to People.

The blog entries painted more macabre scenes.

AD

In January 2015, she posted a poem called “Murder Maddness,” which was republished by the Daily Mail; in it, she wrote that she could hear nothing “but their screaming souls.”

AD

“Unlike the monster I am/That no one can see,” it said. “And what I have become/What I have done to some.

“Someone like me/That no one can see/A psychopath in the dark.”

Authorities confirmed last year that the “Nightmare” blog that had been linked to Martinson was indeed associated with her; but they did not know whether the content posted under the pseudonym “Vampchick” was her original work.

The blog has since been taken offline.

Martinson told police that she was subjected to years of mental, verbal, physical and sexual attacks from her mother’s boyfriends — one of whom, she claimed, burned her with a cigarette and once raped her when she was 9, according to the court documents.

AD

AD

“People didn’t know about the abuse she went through,” Rasmussen, her friend and neighbor, recently told People. “This is a tragedy for everybody involved.”

Martinson said her stepfather was no exception.

Over the years, Thomas Ayers had been accused of assault, kidnapping, child enticement and party to the crime of sexual assault of a child under 15, according to court documents, which noted that he “had numerous prior arrests and convictions.”

Two of Martinson’s sisters told authorities that Ayers would hit them “very hard” with “a thick belt and his hand” — on several occasions until “their buttocks nearly blistered,” according to the documents.

AD

They said he had choked them and had punched one of the girls in the face, giving her a black eye.

One of the girls said Ayers told them he threw their puppy around and “shot and killed him, and fed him to a bear.”

AD

He also abused Martinson’s mother, they said.

The teen told police that her stepfather once climbed on top of her mother, pinned her down, put a gun to head and pretended to sexually assault her, saying “just like your father,” according to court documents.

Court-appointed doctors said Martinson was neglected by her mother, who did not provide “a safe environment for her,” according to the documents.

“We all knew she was having a hard time,” another friend, Jacob Dietzler, told the Milwaukee Journal Sentinel. But news of the killings, he said, “came as a complete shell shock. It was bad.”

AD

On Martinson’s 17th birthday, she texted her 22-year-old boyfriend, Ryan Sisco, to say that she had woken up as her mother was being beaten by her stepfather.

“I can’t take this s— anymore,” she wrote, according to the documents. “He’s gonna kill her if she doesn’t leave soon and I don’t want to be around.”

AD

Martinson wrote in a text that she wanted to kill him.

“Just take one of his guns,” she wrote, “and blow his f—— brains out.”

The day after the double-homicide, Martinson’s three younger sisters were still inside the home with their slain parents.

One of the sisters later told authorities that Martinson had taken two showers to wash away the blood before telling the girls — then ages 9, 8 and 2 — that they were going to play a game, according to court documents.

She said Martinson gave them snacks and juice and then locked them in a bedroom, tying a cord around the door.

They managed to escape and call 911.

When police arrived, Martinson and her boyfriend, Sisco, had already fled.

After a nationwide manhunt, they were arrested outside Lebanon, Ind., according to news reports.

Martinson was charged with homicide and false imprisonment, for locking up her sisters, though the false imprisonment charge was dropped.

AD

Sisco has not been charged in connection to the slayings.

Martinson first pleaded not guilty to first-degree homicide by reason of mental disease or defect, but recently took a plea deal for a lesser, second-degree charge.

The stepfather’s brother, Don Ayers, said he did not agree with the deal.

“The day before the murders, she wrote on Facebook that she wanted to kill them,” he recently told People. “To me, that’s premeditated. They should have left the charges at first-degree murder.”

Ayers said it’s not fair how his brother and sister-in-law have been portrayed.

“Thomas and Jennifer are being judged right now by what she is saying about them, but they aren’t here to defend themselves because she killed them,” he told People. “I think she stretched the truth to save her own neck.”

Martinson’s attorney, Amy Ferguson, declined to comment.

Martinson will be sentenced June 17 and faces a maximum of 120 years in prison.