MGM Resorts International, the company that owns the Mandalay Bay Resort and Casino, is disputing police officials’ timeline of events leading up to and during the mass shooting in Las Vegas last week.

During a Monday news conference, Clark County Sheriff Joseph Lombardo said gunman Stephen Paddock first shot at a hotel security guard six minutes before opening fire from his 32nd-floor room at the Mandalay Bay onto an outdoor country music festival below, killing at least 58 people and injuring hundreds of others. Lombardo also said Paddock had checked into the Mandalay Bay on Sept. 25, three days earlier than police first reported.

This timeline replaced officials’ previous belief that the shooting was already underway when security guard Jesus Campos approached Paddock’s door to his corner suite, spurring Paddock to cease firing on the festival and shoot at Campos before turning the gun on himself.

But MGM offered its own version of the events Thursday.

“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 to the Washington Post. “Metro officers were together with armed Mandalay Bay security officers in the building when Campos first reported that shots were fired over the radio.”

MGM had expressed doubt in Las Vegas police earlier this week after officials announced they were changing their timeline of the events that played out in Paddock’s room on Oct. 1.

“This remains an ongoing investigation with a lot of moving parts,” MGM spokeswoman Debra DeShong said in a statement sent to HuffPost on Tuesday.

“As evidenced by law enforcement briefings over the past week, many facts are still unverified and continue to change as events are under review. We cannot be certain about the most recent timeline that has been communicated [publicly], and we believe what is currently being expressed may not be accurate.”

Story continues

Stephen Paddock shot at a Las Vegas country music festival from a shattered window in his 32nd-floor suite at the MGM-owned Mandalay Bay Resort and Casino. (Photo: Drew Angerer via Getty Images)

An investigator told the Los Angeles Times last week that police now believe Campos, who was wounded by Paddock, first alerted hotel security officials of a gunman on the 32nd floor before the massacre began.

Clark County Assistant Sheriff Tom Roberts told the Times that Campos, who possibly used a hallway phone, “called it in before” Paddock turned his guns onto the music festival.

“He manually called down and he used his radio to call,” Roberts told the newspaper, later adding, “We just don’t know how long it took him to call. He’s getting shot at, he’s running, he’s getting shot, he finds some cover, that’s when he starts calling in.”

MGM argued that police officials’ timeline was “derived from” a report manually created by Mandalay Bay “after the fact without the benefit of information we now have.”

“We are now confident that the time stated in this report is not accurate,” MGM said in its Thursday statement.

As the Post pointed out, MGM’s statement claims police and security officers “immediately responded to the 32nd floor,” where the shooting was carried out, but Lombardo has said police didn’t get to Paddock until 12 minutes after the shooting began.

Paddock, 64, a reportedly wealthy high-stakes gambler, is responsible for one of the deadliest mass shootings in modern U.S. history. While firing at Campos, Paddock shot more than 200 rounds down the hotel’s hallway, according to the Las Vegas Review-Journal. Campos was shot in the thigh.

Lombardo told the Las Vegas Review-Journal on Tuesday that investigators have been in contact with Paddock’s entire “family tree,” including his two ex-wives, combed through Paddock’s suite and reviewed security footage, but have found no information on why Paddock carried out the attack.

Police believe Paddock was the only shooter involved. Lombardo told the Review-Journal on Tuesday that the timeline “could change even more.”

In the statement to HuffPost, MGM’s DeShong said, “We understand the public’s desire for information and the importance of getting our community and the public at large the information they deserve, and we are doing everything we can to support law enforcement’s efforts to do so. Therefore, it is not appropriate for us to comment further at this time on what remains an open matter for law enforcement.”

This story has been updated throughout with information from MGM's Thursday statements.

Also on HuffPost

People hug and cry outside the Thomas & Mack Center after a mass shooting at the Route 91 Harvest country music festival on Oct. 2, 2017, in Las Vegas.

A cowboy hat lies in the street.

VIDEO: Rapid fire from shooter(s) in Las Vegas pic.twitter.com/jgzCTQRUZP — Joel Franco (@OfficialJoelF) October 2, 2017

Las Vegas police search for the gunman while protecting fleeing fans.

Fans run from the Route 91 Harvest festival after a gunman opened fire.

Others dive for cover.

Some fans drop to the ground.

People run from the Route 91 Harvest festival.

People scramble for cover.

HORRIFIC SCENE: Do not let this be called anything else but DOMESTIC TERRORISM. AP reports 2dead 13critical & dozens injured. #MandalayBay pic.twitter.com/q7faKkCPpN — Eduardo Samaniego (@EduSamani) October 2, 2017

A man in a wheelchair is helped away.

People run for cover.

EYEWITNESS: Chilling footage of moment active shooter opened fire on concert goers near Mandalay Bay resort in Las Vegas pic.twitter.com/7OfAwg0ReO — Josh Caplan (@joshdcaplan) October 2, 2017

A person takes cover amid the shooting.

A person runs barefoot from the shooting.

Police officers stop a man who drove down Tropicana Avenue near Las Vegas Boulevard, which had been closed.

A pair of cowboy boots lies in the street outside the concert venue.

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This article originally appeared on HuffPost.