LAS VEGAS (KABC) -- At least two gun shop owners have come forward to say they sold firearms to Las Vegas gunman Stephen Paddock, and said he passed background checks and gave no indication of mental instability.
One store owner in Mesquite, Nevada, where Paddock lived, told ABC News he sold guns to Paddock. He did not specify how many and whether they were used in the shooting.
"We mourn for this tragedy and our thoughts and prayers are with the families of the lost and injured," said Christopher M. Sullivan, the general manager of Guns & Guitars, Inc.
"Mr. Paddock was a customer and purchased firearms from our store; however, all necessary background checks and procedures were followed, as required by local, state, and federal law. He never gave any indication or reason to believe he was unstable or unfit at any time. We are currently cooperating with the ongoing investigation by local and federal law enforcement in any way we can," Sullivan said.
Guns & Guitars, Inc., sells semi-automatic weapons but not fully automatic weapons.
The owner of a gun store in Utah said Paddock visited the store several times this year and bought a shotgun after passing a federal gun background check.
Dixie GunWorx owner Chris Michel said Paddock said that he was new to the area and was visiting local gun shops.
Paddock bought the shotgun in February and last visited the store in St. George, Utah, in the spring. It's a 40-minute drive from where Paddock lived in Mesquite, Nevada.
Michel says he chatted with Paddock to get to know him and make sure there were no signs that he should not be allowed to buy a gun.
Michel says: "There were no red flags."
He added: "I had no idea he would be capable of this."
Paddock has been identified as the gunman in the worst mass shooting in U.S. history.
Investigators say he brought a cache of weapons to the 32nd floor of the Mandalay Bay Hotel, broke open a window and fired on a crowd gathered below at the Route 91 country music festival.
Authorities say at least 59 people were killed and 527 injured.
After officers breached his room, they found him dead, likely of a self-inflicted gunshot.
In the room they found at least 16 weapons, believed to be mostly high-powered rifles, some equipped with scopes.
Recordings from witnesses at the concert indicated hundreds of rounds were fired in multiple rapid-fire bursts.
Authorities also searched his home in Mesquite and found 18 additional firearms, explosives and thousands of rounds of ammunition.
They also found the fertilizer compound ammonia nitrate, which can be used in explosives, in his car.
Police are still investigating to determine all the locations where he obtained the weapons, including one dealer in Arizona.
ABC News and The Associated Press contributed to this report.
Gun dealers: Paddock passed background check to buy weapons, 'no red flags'