Las Vegas law enforcement says they don't believe they could have prevented the massacre Sunday night at the Route 41 Harvest festival.

The death toll of the worst mass shooting in the history of the country has now reached at least 58, with more than 500 wounded. The shooter, Stephen Craig Paddock, 64, of Mesquite, Nevada, opened fire on Jason Aldean concert-goers from his hotel room on the 32nd floor of the Mandalay Bay resort. The shooting spree ended when Paddock took his own life as authorities closed in. When the SWAT team busted through his hotel room door, they found the shooter dead along with a cache of around ten guns.

As Americans grieve the most deadly display of violence in the country since 9/11, many are asking if anything could have been done to prevent Paddock's actions. Clark County Sheriff Joseph Lombardo told reporters in a press conference on Monday that he does not believe authorities could have prevented Paddock from carrying out the heinous act.

"This individual was described as a lone wolf; I don’t know how it could have been prevented," said Lombardo. "We didn’t have any prior knowledge to this individual. It wasn’t evident that he had any weapons in his room. We have determined that there has been employees going to and fro to his room and nothing nefarious was noticed at this point."

So far authorities have not specified any possible motive for Paddocks' murderous campaign. Paddock's brother, Eric Paddock, told the Daily Mail Monday morning that he and his family are "dumbfounded" by the actions, having seen no indications prior to the massacre that his brother was capable of such an act.

"He was just a guy. Something happened, he snapped or something," said Eric Paddock, who lives in Orlando, Florida, and said he does not have much contact with his brother. "He has no political affiliation, no religious affiliation, as far as we know. This wasn't a terror attack."

Statements from authorities seem to confirm Eric Paddock's assessment that it was not an act of terror.

On Monday, ISIS took credit for the attack, claiming the shooter had "converted to Islam several months ago." However, the FBI has shot down that claim, saying they have no evidence that Paddock was connected to any international terrorist group.

The Department of Homeland Security additionally says there's no "specific credible threat" to any other public venues, CBS reports.

Read the interview with the shooter's brother here.

Read more on Stephen Paddock here.