Police announce another Las Vegas shooting timeline update that adds major twist to investigation

Las Vegas investigators have once again revised the timeline of the Oct. 1 Las Vegas shooting, which took the lives of nearly five dozen people and injured more than 500 others.

What do police say now?

Clark County Sheriff Joseph Lombardo said Friday investigators now believe the shooter, Stephen Paddock, shot and injured a Mandalay Bay security guard, Jesus Campos, around the same time he opened fire on concert-goers at a country music festival on the Las Vegas strip, according to the New York Times.

It wasn't clear whether Paddock was already firing on the crowd when he turned and shot at Campos or if he shot him and then turned on the crowd. Paddock had cameras in and around his room so he could monitor police activity.

Police last changed the timeline on Monday, saying that Paddock shot Campos at 9:59 p.m. before opening fire on the crowd at 10:05 p.m. They originally said Campos was shot after Paddock finished firing at the crowd.

Why did they change the timeline again?

Police altered the shooting's timeline after MGM Resorts, the company that owns the Mandalay Bay, publicly disputed the updated timeline and said they did not believe the revised timeline was correct.

Instead, MGM said the 9:59 p.m. report was "manually created after the fact" and not accurate.

"We know that shots were being fired at the festival lot at the same time as, or within 40 seconds after, the time Jesus Campos first reported that shots were fired over the radio," MGM said in a statement on Thursday. Lombardo corroborated this on Friday.

Why is MGM defending themselves so earnestly?

MGM's response will come under scrutiny as lawsuits are prepared. So, the company wants to position themselves as doing everything in their power negate any possible liability. From NBC News:

How exactly the carnage developed remains in the center of the dispute between MGM and the Las Vegas Metropolitan Police Department.

The casino hotel's liability — and when it may have first alerted police to the shooting — is coming under question as potential lawsuits are prepared. The first such lawsuit was filed Wednesday by a shooting survivor against MGM, as well as the concert promoter and the manufacturer of so-called bump stocks, the rapid-fire gun modifications purchased by Paddock.

The two remaining major questions:

1. What was Paddock's motive? Two possible motives have so far been revealed: an undiagnosed mental illness and Islamic terrorism. Both are unconfirmed.
2. Why did Paddock stop shooting when he did? It was more than an hour between his last shot and when SWAT teams breached his hotel door.