The Las Vegas shooter has been identified as 64-year-old Stephen Paddock, responsible for the deaths of at least 50 people and injuring hundreds more at the Route 91 Harvest country music festival.
Paddock is thought to have opened fire on a concert from the Mandalay Bay Hotel in Las Vegas before committing suicide as police closed in on his room 32nd floor of the Mandalay Bay Hotel and Casino across the street from the festival.
Police announced that they were looking for Marilou Danley in connection with the attack, she was later found by authorities and exonerated of any involvement.
The gunman, is thought to have lived locally in Mesquite, Nevada - 90 minutes from Las Vegas. Paddock's $400,00 home has been taped off by police who confirmed that Danley lived with him in what has been described as a retirement area.
Neither had any previous dealings with the police for any crimes.
At 64, Paddock is one of the oldest mass shooter in US history.
At least eight guns and a number of long rifles found in the alleged shooter's room, Las Vegas PD Undersheriff Kevin McMahill said.
The brother of Stephen Paddock says he is "completely dumbfounded" by his sibling's actions, adding that the family are in complete shock.
Eric Paddock, who lives in Orlando, Florida, said his now-deceased brother was just a normal guy who, as far as he knew, held no religious or political affiliation.
He told the Daily Mail that the 64-year-old must have just "snapped" when he allegedly opened fire on a country music concert from the 32nd floor of a Las Vegas Strip hotel.
Paddock said his 90-year-old mother, who also lives in Orlando, is currently in shock and struggling to cope with the news of her son's alleged murderous rampage.
He added that his brother lived a significant distance away – in Mesquite, Nevada – and that the pair did not speak often.
He said the last time they spoke was after Hurricane Irma.
"He's my brother, we don't have a very close relationship but we talk occasionally," he said. "There's no rhyme or reason here, it makes no sense.
"He was just a guy. Something happened, he snapped or something, he was just a guy. He has no political affiliation, no religious affiliation, as far as we know. This wasn't a terror attack."
The death toll which currently stands at 50, is the worst mass shooting in US history, surpassing the 49 who were killed in the Orlando shooting in 2016.
Joseph Lombardo, the sheriff of the Las Vegas Metropolitan police said in a short statement that the "primary aggressor is dead ... the scene is static".