UPDATE 6:30 p.m.: Fifty-nine people are now dead with over 520 injured from the Las Vegas massacre on Sunday, Clark County Sheriff Joseph Lombardo said.
The shooter who opened fire on a crowd attending a music festival in Las Vegas once lived in Florida, records show.
Shooter Stephen Paddock, 64, lived in the Sunshine State for a brief stint, owning a home in Melbourne from April 2013 to May 2015.
Paddock resided in the 55-plus community of Heritage Isle in the community of Viera, which is just shy of 60 miles away from Orlando.
Paddock's brother, Eric Paddock, currently resides in Orlando. His mother lives in Orlando as well.
"He's my brother, we don't have a very close relationship but we talk occasionally," Paddock told the Daily Mail Monday. "There's no rhyme nor reason here, it makes no sense."
According to police reports, Paddock opened fire on a large crowd attending a Jason Aldean country music concert in Las Vegas Sunday evening, killing at least 50 people while injuring more than 500 others.
The numbers started out much smaller, with only two dead, then 20. The current number of dead -- now at 58 -- is said to be a preliminary estimate and could climb as the day goes on.
Paddock's former roommate, Marilou Danley, named early by the Las Vegas sheriff as a person of interest in shooting, has now been cleared. She was out of the country when the attack occurred, according to Monday morning news reports.
Approximately 22,000 people were in the crowd to see Aldean play when the shooter opened fire from the 32nd floor of the nearby Mandalay Bay hotel, spraying hundreds with bullets and causing chaos as concertgoers realized what was happening.
The shooting is the deadliest in modern U.S. history, topping last year’s tragedy at a gay nightclub in Orlando where 49 people died.
Panic washed over concertgoers, many of whom began running to flee the concert, trampling each other to get out of the area. Aldean, still on stage, stopped playing and ran off to take cover from the gunman.
"Tonight has been beyond horrific," Aldean said in a statement posted to Instagram. "It hurts my heart that this would happen to anyone who was just coming out to enjoy what should have been a fun night."
According to Clark County Sheriff Joseph Lombardo, Paddock shot himself before law enforcement officers arrived at the hotel room, which was filled with “numerous” weapons.
KTNV's Beth Fisher, citing a police source and reporting it on Twitter, “said shooter had 8 guns & 2 platforms set up to shoot from + cameras set up to see police arriving.”
Police said Monday afternoon they found 18 more guns, explosives and several thousand rounds of ammunition in Paddock's home.
A motive for the shooting is not yet clear.
"We have no idea what his belief system was," Lombardo said.
President Donald Trump responded to the incident on Twitter Monday morning, offering words of comfort to the victims of the tragedy.
"My warmest condolences and sympathies to the victims and families of the terrible Las Vegas shooting. God bless you!" Trump said.
This is a breaking story. Check back for updates.