Editor's Note: Jesus Campos reappeared on Tuesday, October 17.

Jesus Campos, a security guard at the Mandalay Bay Resort and Casino, vanished from the public eye.

He was hailed as a hero for his actions during the Las Vegas shooting.

His disappearance came after authorities changed key details in the timeline of the massacre.

Jesus Campos, the security guard injured in the Las Vegas shooting and lauded by authorities as an "absolute hero" for his efforts assisting police officers, has apparently disappeared.

In recent days, Campos has fallen off the radar of union leaders, backed out of media interviews, and sparked concern from neighbors who say they have no idea where he is.

Campos was shot in the leg on October 1 as he approached the door of Stephen Paddock's hotel suite on the 32nd floor of the Mandalay Bay Resort and Casino shortly before Paddock opened fire on thousands of concertgoers attending the Route 91 Harvest festival across the street, according to the latest information from Las Vegas authorities. The massacre ultimately left 58 people dead and hundreds of others injured.

Campos' disappearance comes amid a wide-ranging investigation into the shooting that has so far yielded more questions than answers and prompted a proliferation of conspiracy theories. Investigators have still not determined a motive for Paddock's deadly rampage, and Las Vegas authorities have changed their version of the shooting's timeline multiple times.

Officials said Campos was "absolutely critical" to the police response to the shooting by notifying his dispatch immediately and advising officers as they arrived.

Yet as union leaders sought to coordinate interviews between Campos and multiple news outlets, Campus suddenly vanished.

David Hickey, the president of the Security, Police, and Fire Professionals of America union, told media that he was with Campos in a Las Vegas hotel suite on Thursday, ahead of scheduled interviews with CNN, ABC, NBC, CBS, and Sean Hannity's show on Fox News.

But Hickey said Campos abruptly left the suite while Hickey was meeting in a separate room with representatives from MGM Resorts, the Mandalay Bay's parent company. Another union member told Hickey that Campos was taken to a health clinic, but Hickey was unable to reach him.

"We have had no contact with him," Hickey told the Los Angeles Times, adding: "Clearly, somebody knows where he is."

A representative for UMC Quick Care, where Hickey said he was told Campos went, told Fox News they hadn't heard anything about the security guard visiting any of the clinic's eight locations in the Las Vegas area.

When Times reporters visited Campos' reported address over the weekend, they found an armed private security guard, who declined to say who had hired him, and three "no trespassing" signs on the fence and house.

"Nobody knows where he is," Campos' neighbor Jaime Ruano told the Times, adding that Campos was "a hero."

On Friday, Sheriff Joe Lombardo of the Las Vegas Metropolitan Police Department told media that Paddock most likely shot Campos around 10:05 p.m., moments before Paddock opened fire on the crowd of concertgoers through the smashed-out windows of his 32nd-floor suite.

Days earlier, Las Vegas authorities said Campos had been shot at 9:59 p.m., prompting speculation over why six minutes had supposedly elapsed between that shooting and when Paddock carried out his massacre. In his Friday news conference, Lombardo said that the 9:59 p.m. timestamp had been derived from a "human entry into a security log" and that the information was no longer considered accurate.

Lombardo also assailed accusations that law-enforcement officials were either covering up details of the shooting or had been mistaken because of ineptitude.

"In the public space, the word 'incompetence' has been brought forward, and I am absolutely offended with that characterization," he said.

Las Vegas authorities have since sought to shut down speculation about Campos' role in the shooting.

"[Campos] is not missing. He's not under arrest," Larry Hadfield, a Las Vegas police officer, told the fact-checking website Snopes. "We tell people what we know. If they don't believe it but they're going to believe whatever website, then I don't know what else to tell you."