(CNN) -- They thought they had something to prove to someone they found on a ghoulish website, police say. So, two girls lured a third girl into a wooded area in Waukesha, Wisconsin, over the weekend and stabbed her 19 times, according to authorities.
The suspects allegedly left the victim to crawl to her own rescue. The three girls, all 12 years old, were friends.
A bicyclist found the wounded girl alive Saturday, lying on a sidewalk in Waukesha, Police Chief Russell Jack said. She was in stable condition at a hospital Monday.
The girls were trying to impress a certain "Slenderman," according to a criminal complaint. One of the girls encountered the name on a website known as Creepypasta Wiki.
Slenderman is a fictional character and Internet meme that often appears in horror stories, videos and images. One of the suspects told police that Slenderman is the site's supposed leader, and to climb into his realm, a user must kill someone.
On Tuesday morning, a lengthy statement was posted on www.creepypasta.com.
The statement expressed condolences for everyone involved and stressed that the site does not condone or encourage violence in any way. But it also noted that "it's hard to justify pinning blame on an entire genre of writing."
Creepypasta is a play on the term "copypasta," which is derived from the keyboard action "copy-paste." Creepypasta is horror fiction written with the Web in mind and, often, comes in a style that makes it look like a news or true crime story.
Numerous plans of attack
Two girls, Morgan Geyser and Anissa Weier, were arrested hours after the victim was discovered Saturday, the complaint says. They were being held on preliminary charges of attempted first-degree intentional homicide.
Geyser and Weier are being charged as adults and appeared in court Monday. Bail was set for each in the amount of $500,000, Waukesha County District Attorney Brad Schimel said.
Anthony Cotton, Geyser's attorney, told CNN on Tuesday that he's spoken briefly with her. She is housed at a juvenile facility for females, he said, and the girl's family is in "shock."
Geyser has not had a mental evaluation yet, but her lawyer expects her to be given one soon.
Attempts to contact an attorney for Weier were unsuccessful Monday and Tuesday.
The suspects attended the same middle school as the victim and had a sleepover at the home of one of the suspects Friday night, Jack said.
"Both suspects had a fascination with a fictitious character that often posted" to websites dealing with stories about death and horror, the police chief told reporters at a news conference.
According to the criminal complaint, the suspects had been planning the attack since February.
They first thought to kill the victim by placing duct tape over her mouth while she was sleeping and stabbing her in the neck, the complaint says.
Next, the plan was to kill her in a park bathroom where there was a floor drain that could make cleanup easier, it continued.
But, finally, the girls decided to carry out the attack in the park while playing a game of hide-and-seek, the complaint says.
It states: "As they left for the park ... (the victim) was walking in front of them and Geyser lifted up the left side of her white jacket and displayed the knife tucked in her waistband. Weier stated she gave Geyser a look with wide eyes and, when asked what that meant Weier stated, 'I thought, dear god, this was really happening.' "
'One millimeter away' from death
The victim was stabbed near her heart, and she was "one millimeter away from certain death," the complaint says.
When the bicyclist found her, the girl pleaded, "Please help me. I've been stabbed."
She was in extreme pain and could only answer yes or no questions, the complaint says.
Authorities searched for the two other girls, and a sheriff's officer found them walking near Interstate 94, Jack said.
He declined to say whether the suspects had blood on their clothes, but added: "There was evidence that was readily apparent when the two were taken into custody."
That evidence included a large kitchen knife inside a purse that Geyser identified as one of her mother's old purses, according to the complaint.
Mary Ellen O'Toole, a former FBI profiler, described the case as "very unusual -- not just because is involves young females," she said, "but the brutality of it."
CNN's Doug Gross, Shawn Nottingham, Ben Brumfield, Janet DiGiacomo and Kara Devlin contributed to this report.