The gunman who opened fire on a country music festival in Las Vegas did not have help from a second attacker, officials said Friday, but it remains unclear whether he made anyone else aware of his plans in advance.
Police investigators and more than 100 FBI agents have combed through hundreds of leads and hours of video from the Mandalay Bay Resort and Casino to determine why Stephen Paddock, 64, opened fire on the Route 91 Harvest Festival, leaving 58 people dead and nearly 500 others injured.
Unlike the investigations that follow many mass shootings, a study of Paddock's computers, political affiliations, behaviors and finances has not uncovered any clear motive for the attack or any "potential radicalization," Las Vegas Metropolitan Police Department Undersheriff Kevin McMahill said.
"I get it -- we all want answers," McMahill said. "We have looked at everything, literally."
He urged anyone with information about Paddock's movements or plans to call (800) CALL-FBI, saying there could be "a number of people out there that know that something looked out of place."
Disputing a media report published Friday, McMahill also said investigators "do not believe" someone used a key card to enter Paddock's room during a period when his car was not in the Mandalay Bay garage.
A "voluminous amount of video" from the resort has not turned up anyone that police "believe to be a suspect," McMahill said.
In the last year, Paddock -- a retired real estate investor and former IRS agent -- used his apparently extensive financial resources to fund his plans for the attack while also bankrolling his longtime passion for gambling.
Since last October, Paddock bought 33 guns, a haul that could have cost him tens of thousands of dollars. Investigators have wondered whether his weapons spending spree could have escaped notice.
Paddock's girlfriend, Marilou Danley, has said through an attorney that she did not know what he was planning. He bought her a "cheap" plane ticket to the Philippines two weeks before the attack to visit her family, she said.