LITTLETON, Colo. (AP) — FBI officials in Colorado say the woman who made undisclosed threats against Columbine High School is “infatuated” with the 1999 school shooting and is considered armed and dangerous.

The FBI’s Rocky Mountain Safe Streets Task Force issued a notice Tuesday for police to be on the lookout for 18-year-old Sol Pais. It says she tried to buy firearms and that police who come into contact with her should detain her and evaluate her mental health.

The Jefferson County Sheriff’s Office and the FBI say Pais traveled to Colorado on Monday night and was last seen in the foothills west of Denver. It’s not clear where she came from.

The threats led school officials locked the doors of Columbine and about 20 other schools in the Denver area before releasing students for the day.

The Department of Public Safety urged schools urged schools to tighten security.

Saturday marks the 20th anniversary of a mass shooting at Columbine High School that killed 12 students and a teacher.

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