On October 1, Stephen Paddock opened fire on thousands of concertgoers at the Route 91 Harvest music festival on the Las Vegas Strip.

His campaign of terror, which lasted 10 minutes, claimed the lives of 58 people and left hundreds more injured. The incident became the biggest mass shooting committed by an individual in the US, and prompted discussion on the age-old debate of gun law in America.

Paddock, a high-stake gambler, fired hundreds of rounds into the innocent crowd from the 32nd floor of the Mandalay Bay hotel. The 64-year-old accountant and former real estate investor moved 23 rifles, one hand gun and a laptop into his room, over the space of six days in 10 separate bags. It was clear that he planned the assault, but still his motives remain unclear.

However, investigators are beginning to paint a picture of Paddock’s behavior, which they hope will shed light on the reason as to why he committed such a heinous crime. Starting with his laptop, they found some interesting information that has helped them answer some of their many questions.

As investigators scoured Paddock’s hotel room, where he took his own life before being apprehended, they found his laptop. Bizarrely, the device’s hard drive had been removed, something they suspect Paddock did either during or after his violent rampage.

The hard drive is yet to be found by police as they comb through Paddock’s personal belongings. The absence of the hard drive leaves a gaping hole in the investigation as investigators try to fit together the muddled puzzle that is Paddock’s motives.

However, they were still able to glean some information from Paddock’s laptop via his search history.

Investigators have been patiently looking in to Paddock’s past to establish if the sniper had any affiliation to crime or if he were radicalized. They have examined his finances, political stance and social behavior as they try to find answers to the questions we all have had since that fateful night.

But, it was his search history that revealed the biggest clue of all.