The police were armed with revolvers and shotguns. Neither was effective against an enemy atop a 300-foot tower shooting over a chest-high wall.
The populace of U.T. and Austin in 1966 was an armed society. These people felt every right to defend themselves, and they did so in numbers. Among civilians, students and police were those who owned high-powered rifles, many with scopes for long-range targeting. Within 20 minutes, they began to return fire on Whitman, who was forced to give up his place shooting over the wall and from then on shot only through the drain holes at the base of the deck.
The best way to handle a shooter is to shoot back. Blindingly obvious to anyone but a Democrat. But then, Democrats want an unarmed populace because every mass-murderer has been a Democrat or another brand of liberal, left-wing, ideologue.
Source: The Grim Lessons of Charles Whitman