Authorities discovered that Las Vegas, Nevada, shooter Stephen Paddock’s laptop had a missing hard drive during a search of his hotel room at the Mandalay Bay resort, according to a report.
ABC News reports that investigators have not been able to recover the missing device and suspect that Paddock removed the hard drive before shooting himself to death.
Authorities suspect that Paddock bought software that enabled him to erase files from his hard drive but could not confirm he used the software without examining the hard drive, a source told ABC News.
Investigators are struggling to identify a motive behind Paddock’s attack, which killed 58 and injured nearly 500 at a country music festival at the beginning of October.
They are trying to piece together different aspects of his life, examining ties to friends, family, and associates. Authorities have also tried to discern a motive from his travel habits, health, and finances but to no avail.
Unlike other mass shooters, Paddock has not left many traces of evidence.
But he is not the first mass shooter to destroy or conceal his digital footprint.
In 2007, Cho Seung Hui took the hard drive out of his computer and discarded his cellphone before opening fire on 32 people at Virginia Tech.
Steven Kazmierczak, who took the lives of five students at an Illinois college before turning the gun on himself in 2008, removed his laptop’s hard drive and tossed out the SIM card from his phone.
In 2012, Sandy Hook Elementary School shooter Adam Lanza destroyed his hard drive before he gunned down 20 children and six adults at the Newtown, Connecticut, school.
Authorities arrested Paddock’s brother Bruce Wednesday for alleged child pornography possession in North Hollywood, California, following an investigation that began long before Stephen opened fire on the concertgoers.