LOS ANGELES, Oct. 6 (Xinhua) -- Las Vegas Metropolitan Police Department (LVMDP) and FBI Friday announced a new campaign to retrieve key information related to the mass shooting on Sunday as no evidence has shown the shooter's motive.
"If you know something, say something please, call 1-800-Call FBI," Aaron Rouse, Special Agent in Charge of the Las Vegas Division of the FBI, said at a press briefing Friday, pledging "we will not stop investigation until we find truth."
Before Rouse's promise, Clark County Undersheriff Kevin McMahill disclosed that the authorities had probed Stephen Paddock's personal life, political beliefs, social behavior and economic habits, but had not found clear motive for the violence.
Paddock, the 64-year-old gambler and real estate investor, rained down about 1,600 rounds of ammo from the 32th floor suite of Mandalay Bay hotel into a crowd of more than 22,000 people attending Route 91 Harvest Country Music Festival Sunday night, killing 58 concertgoers and injuring nearly 500.
McMahill confirmed at the press briefing which live showed online that there was no other shooter in Paddock's hotel room, and there's no evidence so far anyone else used his room key or anyone else was with him at the resort in the days before the shooting.
Authorities received more than 1,000 leads and took a large amount of video clips captured by the resort's monitor system, he said, but can not make sure if anybody knew the murder's plan in advance.
There's no evidence Paddock was radicalized at any point, McMahill insisted. The Islamic State terrorist group claimed Thursday that he converted to radical Islam six months ago.
McMahill shrugged off many information raised by reporters at the press briefing, saying "We all want answers, rumours and speculation are not helpful to the investigation."
Former Milwaukee Sheriff David Clarke tweeted on Thursday, saying "I've been in law enforcement nearly 40 years & I'm suspicious about everything. We need to engage the public more."