This undated photo provided by Eric Paddock shows his brother, Las Vegas gunman Stephen Paddock. Picture: Courtesy of Eric Paddock via AP

Las Vegas — The top lawman in Las Vegas says the gunman who killed dozens of people at a concert last month fired more than 1 100 rounds.

The newly released estimate from Sheriff Joe Lombardo offers more detail about the deadliest mass shooting in modern U.S. history.

Stephen Paddock killed 58 people and injured hundreds more on October 1 after he shattered windows of his suite on the 32nd floor of the Mandalay Bay hotel-casino and unleashed withering gunfire at the music festival below before killing himself.

Authorities have said they have not determined Paddock's motive or why he stopped shooting. Lombardo says authorities found about 4,000 unused rounds in the suite.

AP