JEFFERSON COUNTY, Colo. (CBS4) – Her threats sparked a massive manhunt and prompted dozens of Denver-area schools to cancel classes on Wednesday. Investigators warned Sol Pais was armed with a pump-action shotgun and considered extremely dangerous. After Pais was found dead, we learned more about how she obtained the weapon.

Sol Pais (credit: Jefferson County)

Jefferson County Sheriff Jeff Shrader confirmed the 18-year-old high school student legally purchased the gun at a store in an unincorporated part of the county, after flying from Florida to Colorado.

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(credit: CBS)

On Wednesday afternoon, the owner of Colorado Gun Broker said Pais bought the gun from his store.

“She did go through the full background check (4473), and was given a clearance by both NCIC and CBI,” Josh Rayburn wrote. “We had no reason to suspect she was a threat to either herself or anyone else.”

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In Colorado, there is no residency requirement for the purchase of a long gun like the one authorities say Pais bought. You can buy one at the age of 18. That is different from a handgun. You have to be 21 to purchase a handgun – and for a handgun purchase you have to show a Colorado ID.

There is also no waiting period for weapons purchases in Colorado and the background check usually takes a matter of minutes.

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Investigators say Pais died from a self-inflicted gunshot wound. She was found Wednesday morning half a mile away from Echo Lake Lodge up Mount Evans Road, near where the road is currently closed for the season.