WATCH: Dianne Feinstein Recalls Milk, Moscone Assassinations

As U.S. senator Dianne Feinstein introduced an assault weapons ban Thursday, she recalled an experience with gun violence early in her political career: the assassinations of gay San Francisco supervisor Harvey Milk and Mayor George Moscone in 1978.

"I was the one that found Supervisor Milk's body, and I was the one to put a finger in a bullet hole, trying to get a pulse," Feinstein, who served with Milk on the Board of Supervisors and succeeded Moscone as mayor, told reporters Thursday. "Once you have been through one of these episodes, once you see what the crime scene is like, it isn't like the movies -- it changes your view of weapons." See video at the bottom of this page.

Feinstein's bill "would ban 158 specific military style rifles, including Bushmaster XM-15 that Adam Lanza used in the mass shooting at Sandy Hook Elementary School in Newtown, Conn., in which 20 children and 6 adults died," the San Francisco Chronicle reports. "It also would outlaw ammunition magazines with a capacity above 10 rounds."

Feinstein sponsored the assault weapons ban that Congress passed in 1994; it expired 10 years later. The new bill has no expiration date.

The senator and other supporters of the ban acknowledge that its path to approval will be difficult, given well-organized opposition by gun-rights advocates. However, it specifically protects more than 2,000 rifles and shotguns used in hunting and sports, a provision aimed at allaying gun owners' fears.