Judge rules against park ranger who used stun gun on dog walker

A park ranger used a stun gun on Gary Hesterberg on Jan. 29, 2012, while he was walking his dogs along a trail at Rancho Corral de Tierra near Montara in the Golden Gate National Recreation Area. A park ranger used a stun gun on Gary Hesterberg on Jan. 29, 2012, while he was walking his dogs along a trail at Rancho Corral de Tierra near Montara in the Golden Gate National Recreation Area. Photo: Courtesy Julia Sherwin Photo: Courtesy Julia Sherwin Image 1 of / 1 Caption Close Judge rules against park ranger who used stun gun on dog walker 1 / 1 Back to Gallery

A federal judge ruled that a National Park Service ranger acted unlawfully with unreasonable force when she used a stun gun on a man who was walking his dogs off-leash after he gave her a false name in unincorporated San Mateo County in 2012.

The incident began the afternoon of Jan. 29, 2012, when Gary Hesterberg, 50, of Montara took his two dogs, a beagle named Jack and a rat terrier named JoJo, on a walk as he’d done many times before in the Rancho Corral de Tierra open space, referred to as the Rancho.

The Rancho always had laws requiring that dogs be kept on-leash, but the court found no evidence that the law had been enforced, and Hesterberg was used to letting JoJo run free. The land had recently been acquired by the Golden Gate National Recreation Area and part of Ranger Sarah Cavallaro’s duty that day, the first day of enforcement, was to “take an 'educational approach or soft enforcement’ with regards to violations of the Rancho’s new rules,” according to court documents.

Cavallaro stopped Hesterberg and talked to him about the new rules. The conversation grew increasingly contentious, and Hesterberg gave the ranger a fake last name because, he testified, “I don’t want to be placed on some offending dog walker ... list.”

The conversation escalated, with Hesterberg and a couple that was also on the trail questioning Cavallaro’s authority. Hesterberg told the ranger that he was leaving and she pulled out a stun gun, telling him he was not free to leave and then radioing for backup, according to court records.

After four minutes with the stun gun pointed at him, Hesterberg said he had a heart condition and again asked what authority he was being held under, to which Cavallaro answered, “the Constitution.”

“That is no kind of answer,” Hesterberg responded, before turning to leave. When he did, Cavallaro fired her stun gun, hitting Hesterberg in the back and buttocks, court records show.

Hesterberg was arrested on suspicion of failing to obey a lawful order, keeping dogs off-leash and providing false information, but San Mateo County prosecutors declined to file charges.

The case garnered national attention when Rep. Jackie Speier ripped the Park Service over its investigation when its own Office of Professional Responsibility failed to take disciplinary action.

Though the court conceded that lying to a police officer is not an offense to be taken lightly, there is nothing inherently dangerous about it, especially in connection to a warning about a leash law violation.

The court also found that Hesterberg, though uncooperative, never posed an immediate threat to Cavallaro or anyone else and that the ranger did not provide an adequate warning that she would shoot him with the stun gun if he tried to leave.

The judge presiding over the case, Jacqueline Scott Corley, found in favor of Hesterberg, awarding him $50,000 in damages for both physical and mental suffering.

Kale Williams is a San Francisco Chronicle staff writer. E-mail: kwilliams@sfchronicle.com Twitter: @sfkale