Maricopa County Sheriff's deputies say they've arrested a 16-year-old girl who had a detailed plot to gun down students at her Mesa high school and then kill herself.
MCSO said she made the threats on a transgender community YouTube channel that said, in part, "I now literally have a plan of seriously hurting ... killing ... murdering people in my high school. And a playlist to do it."
MCSO said they were notified of the post by the Toronto Police Department in Canada late Wednesday night after the owner of the website contacted Toronto police.
The 16-year-old student, who also serves as a student aide at Red Mountain High School, was arrested Thursday morning at her Mesa home. She was scheduled to appear in Juvenile Court at 1:30 p.m. Friday.
CBS 5 is not naming the teen because of her age.
Sheriff's detectives said according to her interview, she was scared because she thought she may carry out the plans detailed in the post and "(expletive) kill everyone."
The girl also admitted to detectives that she had thought about the killings for a while and was planning to "cut the wires to the security carts" on campus to slow down the response during an explosion and shoot people from the other side of a fence.
Authorities found three handguns in her home, including a semi-automatic .40 caliber, a .357 revolver and a .22 revolver.
The girl's parents told detectives that she has a history of mental health issues, has been seen by a psychiatrist and had recently been asking about where the guns were being kept in the house. The girl's father said he was alarmed by the comments and placed trigger locks on each gun and put them in a gun safe.
A neighbor who's known the teen for years said she's a gifted musician and she never showed any violent tendencies.
"She's really nice once you get to know her," said Braydon Barlow. "But, other than that, that's nothing like her. I've never seen her act like that."
A longtime friend who played with her in a band says she recently came out as transgendered.
"I'm shocked. Totally surprised. I've known her forever, since like third grade and I just can't believe it's her," said Red Mountain junior Jacob Stowasser.
Another friend, Jake Betts, told CBS 5 she was a member of the school's Gay Straight Alliance club, or GSA, but that she dropped out at the urging of her parents.
"Just recently she's had a lot of problems. Like personal problems with family and stuff," said Stowasser, without providing details.
The girl is currently being charged as a juvenile for one count of computer tampering and one count of threatening and intimidating. Detectives continue to investigate and say additional charges are possible.
MCSO said at this time they do not believe the school was in "imminent danger."
Red Mountain High School plans to conduct final exams on Friday as scheduled, with an increased presence of security on campus.
Sheriff Joe Arpaio said the threats are not related to last Friday's shooting in Connecticut. Arpaio said the threats were made a week before the mass shooting.
Stay with cbs5az.com for updates on this developing story.
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