Updated at the bottom: Simpson was arrested over the weekend. First posted at 12:32 p.m. on Dec. 21.

They're calling this teen an alleged ninja murderer.

Police say 19-year-old William Gary Simpson Jr. entered 40025 Milkwood Lane in Murrieta at 3:55 a.m. yesterday and fatally stabbed an 18-year-old woman before attacking and wounding her 47-year-old father and a 17-year-old boy who was staying in the home.

Simpson is on the loose, and cops are looking for him, but …

… they discount they ninja aspect of the story as a figment of the media's imagination.

Murrieta police Lt. Tony Conrad told the Weekly today that cops aren't sure if he was wearing a mask and that he was simply dressed in head-to-toe black:

It is fair to say from my point of view that he was not dressed as a ninja.

Simpson.; Credit: Murrieta PD

Simpson.; Credit: Murrieta PD

In any case, there's still a be-on-the-lookout alert (PDF) for Simpson, who is described as 6 feet, 3 inches tall and 120 pounds. The fro in the photo is probably gone, cops say.

He's known to the victims and lived briefly in the home last year, according to police. Murrieta is in Riverside County but is near San Diego County and is not far from Orange County, either.

The murdered teen was identified today as Saskia Burke, a Murrieta Valley High School student.

Saskia Burke.; Credit: Facebook

Saskia Burke.; Credit: Facebook

On her Facebook page the teen Burke quotes what she says is a passage from the book American Gods by Neil Gaiman:

I believe that the future sucks and I believe that the future rocks. I believe that all men are just overgrown boys with deep problems communicating …

…I believe in a woman's right to choose, a baby's right to live, that while all human life is sacred there's nothing wrong with the death penalty if you can trust the legal system implicitly, and that no one but a moron would ever trust the legal system. I believe that life is a game, that life is a cruel joke, and that life is what happens when you're alive and that you might as well lie back and enjoy it.

Her father, also wounded, was ID'd as 47-year-old Paul Burke.

The family is known for taking in wayward teens, although it is not a foster care household, Conrad told us.

Simpson had no place to go in November of 2010 and was invited to stay at the home, he said. The suspect was friends with an “older brother” in the family who is 19.

View Larger Map

The 17-year-old victim, who was not ID'd (probably because he's a minor) is apparently one of those teens the family had taken in.

Both the surviving victims were hospitalized in serious condition, according to a police statement.

Conrad described the weapons as two kitchen knives that police believe the suspect brought with him. He cautioned that it's unknown if Simpson is armed with other weapons.

[Update at 10:43 p.m. Sunday]: Simpson was arrested Friday night at his mother's home in Hesperia, according to the Riverside Press-Riverside. He was being held with no bail on suspicion of murder and attempted murder.

[@dennisjromero / djromero@laweekly.com / @LAWeeklyNews]

Advertising disclosure: We may receive compensation for some of the links in our stories. Thank you for supporting LA Weekly and our advertisers.