Las Vegas gunman was firing on security guard and the crowd crowd at about same time: MGM

The owner of the hotel from which a gunman carried out the deadliest mass shooting in modern U.S. history on Thursday provided a new version of the timeline, suggesting there was no time for hotel staff to warn police.

Stephen Paddock opened fire on Mandalay Bay hotel security guard Jesus Campos and the crowd attending a concert nearby at the same time or within 40 seconds of each other, MGM Resorts International said in a statement.

That account differed from the updated timeline Las Vegas police provided on Monday, when they said Campos had been shot six minutes before Paddock opened fire on the crowd and killed 58 people on Oct. 1.

Las Vegas Metropolitan Police Department spokesman Larry Hadfield said the police would have no immediate comment on the hotel's statement.

MGM, which owns the Mandalay Bay hotel, said the 9:59 p.m. time when police said Campos was shot was derived from a hotel report created manually after the fact without the benefit of information the hotel now has.

"We are now confident that the time stated in this report is not accurate," MGM said. "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."

(Reporting by Keith Coffman; Editing by Jonathan Oatis)