Investigators have still not discovered what motivated Stephen Paddock to embark on the worst mass shooting in modern U.S. history but determined that he researched SWAT tactics ahead of the massacre and investigated other possible targets.
Clark County Sheriff Joe Lombardo also told reporters Paddock acted alone.
Lombardo made public a preliminary report into the shooting and said he does not expect charges to be filed against Paddock's girlfriend, Marilou Danley, who had been previously called a person of interest in the case. Investigators also found that Paddock had possessed child pornography.
Paddock's online searches before the shooting included research into SWAT tactics and for other potential public venue targets — and he took photographs of some potential sites, the sheriff said. The searches also included the number of attendees at other concerts in Las Vegas and how many people go to Santa Monica's beach.
The sheriff and the FBI have said they found no link to international terrorism. They said they believe Paddock meticulously prepared and concealed his plan to fire assault-style weapons from the 32nd floor of the Mandalay Bay hotel into a crowd of 22,000 people attending the Route 91 Harvest Festival music below.