A computer found in the hotel room from which Stephen Paddock opened fire on Las Vegas concertgoers was missing its hard drive, according to ABC News.

In the wake of the deadliest mass shooting in American history, investigators have still struggled to assign a motive to Mr Paddock. Information contained on the laptop’s hard drive many have helped piece together that puzzle.

Investigators also learned Mr Paddock had purchased software used to erase hard drives but were not sure if he used it, the news network reported. In a revelation that seems to point Mr Paddock’s tactics more than his motives, investigators combing through his internet history found a search for a police tactic used to break into rooms, the Wall Street Journal reported.

A gambler who appeared to be a stranger to his neighbours, Mr Paddock amassed dozens of guns and a stockpile of ammunition before gunning down 58 people at a country music concert and injuring hundreds.

Unlike some other mass killers, Mr Paddock did not leave behind a note, manifesto or video explaining his actions.

His brother, Eric Paddock, has described the shooting as a shock, telling reporters it “makes no sense” and characterising his brother as an “intelligent” man who “took care of the people he loved”.

Las Vegas shooting – in pictures Show all 15 1 /15 Las Vegas shooting – in pictures Las Vegas shooting – in pictures People scramble for shelter at the Route 91 Harvest country music festival after gun fire was heard Getty Las Vegas shooting – in pictures People carry a person at the Route 91 Harvest country music festival after shots were fired David Becker/Getty Las Vegas shooting – in pictures People run from the Route 91 Harvest country music festival after gun fire was heard David Becker/Getty Las Vegas shooting – in pictures A handout photo released via Twitter by Eiki Hrafnsson (@EirikurH) showing concertgoers running away from the scene (C) after shots range out at the Route 91 Harvest festival on Las Vegas Boulevard EPA/Eiki Hrafnsson Las Vegas shooting – in pictures People lie on the ground at the Route 91 Harvest country music festival after hearing gun fire Getty Las Vegas shooting – in pictures A man in a wheelchair is taken away from the Route 91 Harvest country music festival after hearing gun fire David Becker/Getty Las Vegas shooting – in pictures People stand on the street outside the Mandalay Bay hotel near the scene of the Route 91 Harvest festival on Las Vegas Boulevard EPA/Paul Buck Las Vegas shooting – in pictures FBI agents confer in front of the Tropicana hotel-casino after a mass shooting during a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures Las Vegas police run by a banner on the fence at the Route 91 Harvest country music festival grounds after shots were fired David Becker/Getty Las Vegas shooting – in pictures An injured person is tended to in the intersection of Tropicana Ave. and Las Vegas Boulevard after a mass shooting at a country music festival Ethan Miller/Getty Las Vegas shooting – in pictures Metro Police officers pass by the front of the Tropicana hotel-casino after a mass shooting at a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures A woman sits on a curb at the scene of a shooting outside of a music festival along the Las Vegas Strip AP/John Locher Las Vegas shooting – in pictures A cowboy hat lays in the street after shots were fired near a country music festival in Las Vegas Getty Las Vegas shooting – in pictures Las Vegas Metro Police and medical workers stage in the intersection of Tropicana Avenue and Las Vegas Boulevard South after a mass shooting at a music festival on the Las Vegas Strip Reuters/Las Vegas Sun/Steve Marcus Las Vegas shooting – in pictures Sheriff Joe Lombardo (2-R) speaking during a press briefing in the aftermath of the active shooter incident on Las Vegas Boulevard EPA

“My heart is destroyed, for all these people, but I can't tell you why Steve did what he did,” Eric Paddock told reporters soon after the massacre.

Las Vegas attack: Footage shows moment crowds take cover

His girlfriend Marilou Danley expressed a similar sense of bewilderment, describing the killer as a “kind, quiet, caring man” after she returned to the United States and was questioned by the FBI.