The teenager who entered a Colorado high school with a .12 gauge pump action shotgun and critically wounded a classmate before killing himself also was armed with a machete, three molotov cocktails and more than 125 rounds of ammunition, the Arapahoe County Sheriff’s Office said Tuesday.

In addition, Karl Pierson, 18, had used an indelible marker to write the Latin phrase “”Alea iacta est” – meaning “the die has been cast” on the inside of his forearm. The phrase, which Julius Caesar supposedly uttered after crossing the Rubicon River, is generally taken to mean events have passed the point of no return.

The sheriff’s office also said Pierson had written five separate letters and numbers on his arm, which correlated directly with the school library and specific classrooms in the area of the library/media center. Authorities took this to signal Pierson planned to attack the five areas.

Pierson apparently fired his weapon five times immediately after entering Arapahoe High School in Centennial Friday afternoon, hitting only 17-year-old Claire Davis. He then died from a self-inflicted gunshot inside the library/media center.