More than a week has passed since lone gunman Stephen Paddock opened fire upon 22,000 people at a Las Vegas music festival, leaving 58 people dead and more than 500 injured.
The horrific attack is now considered the deadliest mass shooting in US history.
The officers that stormed Paddock’s room at the Mandalay Bay Hotel have now spoken out about the mass shooting and the chilling note they discovered.
Speaking to 60 Minutes in the US, officer David Newton described finding a note near the shooter’s platform.
“I did notice—a note on the nightstand near—his shooting platform,” he said, CBS reports.
“I could see on it he had written the distance, the elevation he was on, the drop of what his bullet was going to be for the crowd. So he had had that written down and figured out so he would know where to shoot to hit his targets from there.”
Officer Newtown continued: “[He] must have done the calculations on line or something to figure out what his altitude was going to be and how high up he was—how far out the crowd was going to be and what at that distance and what the drop of his bullet was going to be.”
As news.com.au reports, the officers were the first to see Paddock’s body and the enormous number of weapons and ammunition he had stockpiled prior to the attack. The gunman was found with 23 guns; some of them had been modified to fire uninterrupted like an automatic weapon.
Paddock’s motives are yet to be determined.
This article originally appeared on Marie Clare.