Wisconsin school shooter Natalie Samantha Rupnow was obsessed with a sick website called Watch People Die, it has been reported.
The 15-year-old was one of more than 3 million members who visited the disturbing platform where users post graphic and upsetting videos of people getting shot to death, run over, or killed in other brutal ways, the New York Post reports.
It also includes videos of international incidents like ISIS beheadings and other school shootings - of which Rupnow had a particular fascination.
She allegedly posted under the username @Crossixir, and is said to have commented on a video of an apparent suicide by hanging: Gotta be thinking of something while hanging himself.
When another member then asked her to explain, Rupnow wrote: I wonder what a lot [of] people think before they die, you know?
Like just simply, if its if they want to die at all or just nothing, or either perhaps just sex or something stupid, she replied, according to the Post.
Only thing I would bother to think of is, "Just do it already" if I was killing myself, but depends on the situation, Rupnow wrote.
About a month ago, she also allegedly posted a comment on a video of a man jumping through a window, Fat version of Liam Payne, referring to the former One Direction singer who plunged to his death from a Buenos Aires hotel balcony in October.
Natalie Samantha Rupnow was reportedly a member of a website called Watch People Die
She had a particular interest in school shootings, according to the New York Post
The website includes graphic and upsetting videos of people getting shot to death, run over, or killed in other brutal ways
Other videos on the site include suicidal man offs himself in front of cops and worker gets crushed trying to stop a forklift falling over.
But the @Crossixir username had been banned by the site as of Wednesday morning, in the aftermath of the school shooting that took the lives of 14-year-old Rubi Patricia Vergara and Abundant Life Christian School substitute coordinator Erin West.
Six others were wounded in the shooting, and two were left in critical condition.
A motive for the shooting remains unclear, as police say it seems to have been a combination of factors.
Some have asked if people were specifically targeted. Everyone was targeted in this incident, and everyone was put in equal danger, Madison Police Chief Shon Barnes said, according to CNN.
Rupnow had apparently planned out the attack along with 20-year-old California resident Alexander Paffendorf, who was detained by FBI agents on suspicion of plotting to coordinate a mass shooting at government buildings in conjunction with the school shooter.
During an FBI interview, Paffendorf admitted to the FBI agents that he told Rupnow that he would arm himself with explosives and a gun that he would target a government building, the order says.
It notes that FBI agents saw the messages from Paffendorf to Rupnow.
Rupnow opened fire at Abundant Life Christian School just before 11am on Monday
Police arrived moments later and found the shooter wounded and recovered the weapon
But it is unclear how Rupnow knew Paffendorf, and whether any of the victims in the school shooting were specifically targeted.
Lyndsay OConnor, a mother of two survivors, had previously suggested that the regular study hall teacher, who was not there due to a planned absence, may have been Natalies target - though her idea has not been verified by police.
We dont know if her target was the original teacher or just the kids in the class. She would have had to walk by the door and the door was open, OConnor said.
Rupnow had two handguns with her during the attack but only used one to carry it out, Barnes revealed Wednesday, noting that he does not know how the teenager obtained the weapons.
We may never know what she was thinking that day, but we will do our best to try to add or give as much information to our public as possible, he said.
Erin M West, 42, worked at Abundant Life Christian School as the substitute coordinator before she was gunned down
The school shooting took the life of 14-year-old Rubi Patricia Vergara
Police have previously said they received a call at 10:57am Monday morning, and within three minutes, county sheriffs deputies had arrived at Abundant Life Christian School, which educates about 420 students. Local police arrived seconds later.
At 11:05am, they said that theyd found the shooter wounded and recovered the weapon. Rupnow was pronounced dead on the way to hospital.
Simultaneously, fire department workers got to the scene and began to care for the victims.
Authorities raided the Rupnows Wisconsin home after the tragedy, and Natalies father has been reportedly compliant with the ongoing investigation.
Investigators have been trying to figure out if the mass shooters parents, Jeff and Melissa, had any involvement or contributed to Natalies actions.
The shooters parents, who are divorced, jointly shared custody of their child - but Natalie primarily lived with her 42-year-old father.