A trained sharpshooter firing from atop the University of Texas Tower in 1966 introduced many Americans to mass casualty attacks, but almost all of the large-scale shootings since then — including Sandy Hook and Orlando — have taken place at ground level with the gunman killing from relatively close range.

One result: Even as mass shootings became more frequent and police departments expanded training on how to confront a gunman, officers were typically coached on close-quarters assaults taking place on the first couple of floors of schools, shopping malls and office buildings.

Then came Sunday night, when a gunman, identified as Stephen Paddock, opened fire from the 32nd floor of a Las Vegas hotel, targeting a crowd at a concert some 500 yards away. At least 58 people were killed and about 500 others wounded and injured.

Former and current law enforcement chiefs and other experts predicted that Sunday’s shooting could alter the training at many police forces to include more of a focus on the threat posed by high-rise snipers or others who kill from long distances, the New York Times reports.