Updated

At least one witness is shaking her head in disbelief at a federal park ranger's use of a stun gun over the weekend on a Northern California man accused of walking his two small dogs without a leash in violation of park rules.

The National Park Service said the ranger hit Gary Hesterberg with the stun gun on Sunday at Rancho Corral de Tierra in San Mateo County after Hesterberg gave her a false name and then tried to walk away.

But Michelle Babcock told the San Francisco Chronicle the ranger never gave Hesterberg an explanation as to why he was being detained and then hit him with the stun gun in the back.

"He just tried to walk away," Babcock said. "She never gave him a reason. ... It didn't make any sense."

Hesterberg was arrested on suspicion of failing to obey a lawful order, having dogs off-leash and knowingly providing false information, according to Howard Levitt, a spokesman for the park service.

Levitt said the ranger, who has not been identified, asked Hesterberg to remain at the scene, and he repeatedly tried to leave. She was able to stop him after deploying the stun gun, Levitt said.

The ranger was trying to educate residents about the leash requirement, he said. Rancho Corral was recently incorporated into the Golden Gate National Recreation Area, which last year proposed tighter rules on dogs.

Leashes would be required in open spaces where dogs currently roam untethered, and some popular dog-walking areas would be closed to canines entirely under the proposal, which has been criticized by dog owners.

Park service officials and environmentalists said they want to protect some 1,200 native plant and animal species, including the Snowy Plover, a federally endangered shorebird.

A call to Hesterberg by the Chronicle was not returned.