The revised timeline given by investigators for the Las Vegas massacre raises questions about whether better communication might have allowed police to respond more quickly and take out the gunman before he could kill and wound so many people.
On Monday, Sheriff Joe Lombardo said Stephen Paddock shot and wounded a Mandalay Bay hotel security guard outside his door and sprayed 200 bullets down the hall six minutes before he opened fire Oct. 1 from his high-rise suite on a crowd at a country music festival below.
That was a different account from the one police gave last week: that Paddock shot the guard, Jesus Campos, after unleashing his barrage of fire on the crowd, where 58 people were killed and hundreds were injured.
"This changes everything," said Joseph Giacalone, a professor at John Jay College of Criminal Justice and a former New York City police sergeant. "There absolutely was an opportunity in that timeframe that some of this could've been mitigated."
The sheriff had previously hailed Campos as a "hero" whose arrival in the hallway may have led Paddock to stop firing. But on Monday, Lombardo said he didn't know what prompted Paddock to end the gunfire and take his own life.
Police released few details about the new timeline and did not respond to questions from The Associated Press, including whether anyone from the hotel called 911 to report the hallway shooting.
"Our officers got there as fast as they possibly could, and they did what they were trained to do," Assistant Sheriff Todd Fasulo said.
A spokesman for MGM Resorts International, which owns the Mandalay Bay hotel, declined to comment Tuesday, and a representative for Campos' union didn't immediately respond to a message seeking comment.
But the sheriff has said that Las Vegas police officers searching the hotel for the gunman during the attack did not learn the guard had been shot until they got off the elevator on the 32nd floor and met him in the hallway.
Nicole Rapp, whose mother was knocked to the ground and trampled by panicked concertgoers as bullets rained from above, said she's "having a hard time wrapping my head around" why police changed the timeline of the shooting.
"It's very confusing to me that they are just discovering this a week later," she said. "How did we not know this before? It's traumatic for the victims and their families not to be sure of what happened."
Fasulo explained the change in the timeline by saying that dozens of investigators have been using different sources of information -- including surveillance video, computers, police body cameras, cellphones and interviews -- and that not all clocks were in sync.
Last week, police said Paddock had shot at concertgoers for 10 minutes and stopped firing around 10:15 p.m. The first officers arrived on the 32nd floor at 10:17 p.m. and encountered the wounded guard at the elevator bank about a minute later, police said.
Police said Paddock used "bump stocks" to accelerate his shooting. The devices replace the stock and pistol grip and allow a weapon to fire continuously, mimicking a fully automatic firearm.
The Brady Center to Prevent Gun Violence has filed a lawsuit against the makers and sellers of bump stocks on behalf of the shooting victims. The lawsuit claims that the leading manufacturer of the devices misled federal authorities about their intended purpose and marketed them to gun enthusiasts who wanted the experience of firing a fully automatic weapon that is otherwise greatly restricted under federal law.
The lawsuit was filed Friday in Clark County District Court in Nevada. It has three named plaintiffs -- all victims of the shooting -- and seeks class-action status.
Slide Fire Solutions, the Texas-based company that is considered the top manufacturer of bump stocks, did not return an email message sent Tuesday through its Facebook page seeking comment. Its voice mail box was not accepting messages, and the company has not commented since the shooting took place.
Avery Gardiner, co-president of the Brady Center, said bump stock manufacturers had told federal regulators that the bump stock was intended only to assist gun owners with arm mobility issues.
"But when they marketed it to the public, they said it's because fully automatic weapons are fun," Gardiner said. "So what their product is designed to do is subvert federal law on machine guns, and that's irresponsible."
However, the gun industry has broad protections from lawsuits. The Protection of Lawful Commerce in Arms Act was enacted in 2005, protecting gunmakers and dealers from being held liable whenever a crime is committed with a firearm.
But in this case, Gardiner said, that liability wouldn't apply because Slide Fire manufactures neither firearms nor ammunition.
Since the shooting, a bipartisan mix of members of Congress have called for legislation to crack down on bump stocks. A House measure introduced Tuesday with 20 co-sponsors -- 10 Democrats and 10 Republicans -- would ban the manufacture, sale and use of bump stocks.
House Speaker Paul Ryan of Wisconsin said changing the law on bump stocks is "something we need to look into." The National Rifle Association, the nation's largest gun-lobbying group, called on the Bureau of Alcohol, Tobacco, Firearms and Explosives to revisit the devices and determine if they should be subject to greater restrictions.
Information for this article was contributed by Michael Balsamo, Ken Ritter, Sally Ho, Anita Snow and Lisa Marie Pane of The Associated Press; and by Justin Blum of Bloomberg News.
A Section on 10/11/2017