Sienna Johnson: 5 Fast Facts You Need to Know

One of the teen suspects in an alleged plot to shoot up a Colorado high school has been named. Officials in Douglas County charged 16-year-old Sienna Johnson as an adult on January 5. She’s accused, along with another unnamed teenager, of planning to attack students and faculty at Mountain Vista High School in Highlands Ranch, Colorado, in December. The town is about 20 miles south of Denver.

Here’s what we know so far:

1. Johnson Allegedly Told Detectives That if She Was Set Free, She Would Try to Do it Again

The Denver Post reports that the criminal affidavit in the case has been sealed. ABC Denver’s Jennifer Kovaleski reported that Johnson allegedly told investigators that if given the chance, she would have hatched the plot again, but would have been more discreet, reports NBC Denver’s Chris Cheline. Kovaleski later tweeted that Johnson is charged with conspiracy to commit murder and conspiracy to commit murder after deliberations.

2. Johnson Wrote on Her Blog That Her Life Turned for the Worse When Her Father Remarried

Sienna Johnson Tumblr Page


According to her page on Weebly, Johnson was born three months premature in October 1999. She has an older sister. Since she was in the 5th grade, Johnson has lived in Colorado, having lived in Florida and South Carolina previously. She was born in Colorado. Johnson writes after moving back to her home state:

Things were just really difficult. I was angry because I didn’t have the “normal” family and I was always getting shuffled around between my mom’s and dad’s. At age 10 my dad gave me my first drum set to help me let out my frustration and express myself.

Punk rock and hardcore music and art was the perfect expression for me. I spent all my time playing guitar, drumming, writing, and drawing and painting.

Johnson also writes that in 7th and 8th grades she became more rebellious and had been kicked out her father’s home. Even after moving in with her mother, she says she still didn’t like being told what to do. Despite all of this, Johnson “won multiple awards for art and writing.” The blog posting ends with the words:

I still put all my time and energy into the things I enjoy most and hope to be the best I can be.

3. Prosecutors Said Johnson Had Harmed Her Pets in the Past & Had a BB-Gun for Target Practice

ABC Denver’s Jennifer Kovaleski reports that during court proceedings the prosecution called Johnson “extremely violent.” Kovaleski said that Johnson had bought a BB-gun to target practice and had harmed her pets. The prosecution also asked for no bond on Johnson, saying that she had a detailed map of where students and staff would be. The bond was later set at $1 million, with the DA adding that Johnson had shown “no remorse,” reports NBC Denver.

ABC Denver reports that Johnson’s defense lawyers are fighting media requests to unseal the documents in the case. In a statement, attorney’s said:

There is no direct evidence in this case of Defendant’s possession of any weapons, bombs, or incendiary devices. Instead, the prosecution’s theory hinges upon entries written in Defendant’s personal journal, which was seized by law enforcement without a warrant and without consent of either Defendant or her parents.

The journal referenced was a diary that Johnson kept as part of ongoing therapy, according to ABC Denver. Lawyers added that the acquisition of Johnson’s cell phone and its contents had been unlawful. Douglas County Sheriff Tony Spurlock countered that due to the “severity of the situation,” the detectives’ actions were warranted.

4. Her Co-Defendant Is Still Undergoing Psychological Evaluation & Has Not Been Named

The other girl who is accused in the plot has not been charged as an adult yet pending a psychological evaluation. Judicial District Attorney George Brauchler said that review would be “very important for us to consider,” reports the Denver Post. The Post further reported that the other suspect didn’t speak during her court appearance on the morning of January 5. Her next hearing is on January 14.

5. The School Is Just 10 Miles Away From Columbine

 (Getty) President Obama referenced the Columbine atrocity in his January 5 remarks on gun control.

President Obama referenced the Columbine atrocity in his January 5 remarks on gun control. (Getty)

In December, the Denver Post reported that the Douglas County sheriff’s office had been alerted to the alleged plot via a text-a-tip scheme in the area. Online records show that the school has an enrollment of just over 2,000 students. It was opened in 2001. According to, Mountain Vista has a rating of 8/10. The town of Highlands Ranch is less than 10 miles south of Littleton, where the infamous Columbine High School massacre took place in 1999. That shooting, which claimed the lives of 13 people, was referenced on the same day that Johnson was charged by President Obama in his new executive action on gun background checks.