Criminal investigation

Las Vegas Police Release Final Report on Massacre, With Still No Idea of Motive

The man who committed the deadliest mass shooting in modern American history when he opened fire from his Las Vegas high-rise hotel room had no clear motive, Las Vegas police said as they announced Friday that they had concluded their 10-month investigation.

A 187-page report examining the Oct. 1 attack on a country music festival determined that the gunman, Stephen Paddock, acted alone. At a news conference, Sheriff Joseph Lombardo of Clark County said his team had extensive information about the perpetrator’s actions in the days before the shooting.

But, he said, “we have not been able to definitively answer the ‘why.’”

Fifty-eight people died in the attack, and the report said that 887 people sustained documented injuries. Mr. Paddock, 64, a high-stakes gambler, spent days carrying an arsenal of guns into the Mandalay Bay Resort and Casino across the street from the festival, before randomly shooting concertgoers below. He then killed himself.