Could Vegas cops have acted sooner?

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 injured.

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. How crucial were the minutes that elapsed before the massacre began?

“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.”

Giacalone added: “By engaging the shooter ahead of time during this event, it could’ve saved a lot of heartache.”

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.