After Pais was reported as missing, Miami police discovered her alleged infatuation with the Columbine High School massacre, particularly with its perpetrators, Eric Harris and Dylan Klebold.
Pais was taking Honors English and Advanced Placement Studio Art classes and "did not strike classmates or teachers as deeply troubled".
[3] Pais appeared to have stopped writing journal entries in November 2018, but resumed in February 2019, in which she wrote, "The last few days have been especially painful and tumultuous, which kickstarted me again to start reviving my plans and getting on with them".
Pais left her house around 6:15 a.m. on Monday, April 15, and texted her mother approximately 15 minutes later, telling her that she "was going to attend an art history review after school" to explain her absence later in the day.
According to this Uber driver, Pais "had no food or water and only minimal clothing," and had a "green rifle case" with a "bird hunting gun".
After the manhunt became public, it quickly made national headlines, with hundreds calling the FBI claiming they had seen Pais panhandling, buying a gun, or outside of Columbine High School.
With the FBI finding no trace of Pais by the end of the day, Columbine and several dozen other schools closed on April 17, keeping more than 500,000 students across Colorado home.
[7] An audit by the Department of Justice Office of the Inspector General on the incident was conducted after pressure from lawmakers, which suggested upgrades to the FBI's National Instant Criminal Background Check System (NICS).
[11] In 2024, state lawmaker Tom Sullivan raised the case to argue for a mandatory waiting period for Colorado gun buyers.