In the wake of a deadly mass shooting in Las Vegas, many questions are arising about the type of gun that the suspect used to open fire on a crowd gathered at a concert.

Gunman Stephen Paddock, 64, was found dead by officers who stormed his 32nd-floor room at the Mandalay Bay Resort and Casino. When it was all over, authorities said Paddock had killed at least 59, wounded 527 more after prompting chaos as the panicked crowd scrambled for cover amid the deadliest mass shooting in modern U.S. history.

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But now, attention has turned to the weapon Paddock used as people question whether it was an automatic weapon, or if it was modified to become one.

Authorities in Las Vegas reported Paddock arrived in the city fully-loaded with an arsenal of military-grade weapons. Police haven't specified the type yet, but law enforcement sources told media outlets at least one of the guns was fully automatic.

Abubey went to local gun experts at Stoddard's Range and Guns who watched and listened to video from that night, to weigh in.

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"It certainly sounds like an automatic gunfire," said COO Ken Baye. "A semi-automatic gun doesn't sound like that. You don't have the rapid gun fire that you hear here. Semi-automatic is you pull a trigger, it fires, you pull a trigger again. This is in rapid sequence and that's what a machine gun, an automatic weapon sounds like."

if Paddock's weapon was indeed automatic, it raises the question of where he got it from, and whether it was legal. In the United States, it's illegal to own or sell an automatic weapon made after 1986 to the average person who's not law enforcement or military. But there some out there that were registered before 1986 available for purchase legally, but it's rare and not cheap.

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Gun experts estimate they can sell anywhere from $20,000 up towards a million dollars. Buyers also have to go through an extensive background check on the federal level, including submitting fingerprints, paying a $200 tax, registering the serial number of the weapon and in some cases getting a signature from a local sheriff or police chief.

It's not known whether Paddock went through this process, but family did confirm that the gunman was wealthy. Also, police said he had barely anything on his record, other than a traffic citation, so it is plausible that he got the weapon legally.