Police reveal new development in Las Vegas shooting. This could be a game-changer.

Las Vegas police on Monday revealed that Stephen Paddock shot Mandalay Bay security guard Jesus Campos six minutes before opening fire on the crowd below — and the police now have no idea why he stopped shooting at the crowd when he did.

What did the latest briefing say?

Clark County Sheriff Joseph Lombardo revealed Monday during a news conference that Campos did not distract Paddock from focusing on the massacre, noting that Paddock shot Campos before opening fire on the crowd.

Lombardo noted that on Oct. 1, Campos was on Paddock's floor investigating an open door alarm that had gone off in another room. The sheriff also revealed that Paddock shot Campos in the leg at 9:59 p.m., and asserted that Paddock had seen Campos on one of the surveillance cameras he had set up to monitor the area.

At 10:05 p.m., Paddock began firing at the crowd and continued for anywhere between 9 and 11 minutes, killing almost 60 people and injuring nearly 500 others in the attack.

Lombardo said Campos' actions still assisted officers in helping to "pinpoint the location of the suspect," but added that the department now has no idea what prompted Paddock's ceasefire.

Lombardo said investigators still had not uncovered a motive for the 64-year-old Paddock’s attack and had found “zero” evidence of a second gunman.

Why is this significant?

This latest development is a bit of a departure from the initial police timeline of events, which asserted that Campos approached Paddock's room while the shooting was underway.

Initial reports alleged that Campos was responsible for distracting Paddock and that after shooting Campos through the hotel room door, Paddock stopped firing on the crowd.

This, however, is not the case and begs the question of why Paddock stopped shooting at the crowd below.

What's new in the updated police timeline?

According to the Las Vegas Metro Police Department's updated timeline:

• 9:59 p.m.: Campos approaches the suspect's room after being notified that an open door alarm had been tripped on the same floor. Campos is shot in the leg and injured. He notifies hotel security, according to Lombardo. (This new information contradicts initial reports, which suggested that Campos approached Paddock's room during the shooting, prompting him to cease firing on the crowd.)
• 10:05 p.m.: Paddock begins firing bullets at the crowd.
• 10:12 p.m.: Two officers arrive on the floor below Paddock and determine that gunfire is coming from above.
• 10:15 p.m.: Paddock stops firing on the crowd.
• 10:17 p.m.: Two officers arrive on the 32nd floor after leaving the 31st.
• 10:18 p.m.: Campos, who was shot nearly 20 minutes prior, tells law enforcement that he has been shot and provides them with the location of Paddock's room.
• 10:26-10:30 p.m.: Eight more officers arrive on the scene and clear the entire 32nd floor.
• 10:55 p.m.: Officers approach Paddock's room.
• 11:20 p.m.: Paddock's door is stormed and law enforcement enters, only to find the suspect dead.
• 11:27 p.m.: Officers breach a second room in Paddock's suite, but discover that it is vacant.