Updated

The head of the National Park Service defended his decision to let Occupy protesters camp out in a park in the middle of Washington, D.C., though he said Tuesday the group will be given one last warning before being evicted.

NPS Director Jonathan Jarvis testified to the House Oversight and Government Reform subcommittee on the District of Columbia that protests are a right under the First Amendment, although he acknowledged that some homeless people "have taken advantage of the situation."

He added that this is not the first time the Park Service has allowed protesters to remain for weeks at a site.

"Whatever they are protesting is irrelevant to our decisions. Our decisions are based on the totality" of the circumstances, he said.

But Republican lawmakers, who questioned whether Jarvis' decisions were politically motivated, said an exception had been made for a group that for all intents and purposes is camping, not protesting, and contended that the National Park Service was unequally enforcing the law.

"It's not your job to determine which protest group, how to treat protest groups differently. They are breaking the law. Why aren't you enforcing the law?" asked Rep. Joe Walsh, R-Ill.

"Camping is not a First Amendment activity. It is a violation of law. Sleeping (in a national park) is not a First Amendment activity, it is a violation of law," said Rep. Darrell Issa, R-Calif., chairman of the House Oversight and Government Relations Committee.

Issa, who noted that park police in other sites are permitted to remove trespassers at gunpoint if they have to, said NPS has a clear requirement to prohibit camping on federal property. He said he was disappointed that the agency was ignoring its own rules.

"I believe the National Park Service has allowed the protesters to camp indefinitely for ideological reasons," he said.

The is a ban on camping in the park, but Jarvis suggested there is a gray area between constitutionally protected protests and illegal camping.

Jarvis, who testified that he regularly briefs Interior Secretary Ken Salazar on the decisions being made about the campsite, insisted none of his decisions are imposed from above.

"Absolutely not," Jarvis said. "I am not taking direction on this (or) on how the site should be handled."

District of Columbia officials, including the city's deputy mayor for public safety and justice, testified Tuesday that Metro police have arrested 68 Occupy D.C. protesters since they began camping out at the 1.66-acre park in the middle of the city. A couple dozen others have been arrested by other law enforcement agencies.

Deputy Mayor Paul Quander said overall the protesters have been mild mannered, but on a few occasions, "the practice of the protesters has become very aggressive and dangerous, resulting in injuries and situations resulting in law abiding citizens being unable to exit buildings or travel on our public roadway."

Quander gave an example of the Conservative-PAC annual meeting held at the city's convention center late last year in which protesters barricaded the doors and shouted taunts at the crowd assembled inside the hall. In an hasty effort to get out of the melee, a motorist outside the building struck three of the protesters.

Quander said that it's not unusual for demonstrators to use those tactics.

"The point of any protest is to exercise a constitutional right," he said, "and at the same time attract attention to the cause. If the sheer numbers do not demand notice, experience has shown us that escalating tactics may be used to garner attention."

Occupy protesters have been camping out since October at the historic McPherson Square Park. Police have responded to the site for several violations -- including to a report that a toddler had been abandoned there. Neighbors have complained that the campers, who have taken the NPS to court to remain at the site, are attracting vermin and stealing from them.

Timothy Zick, a professor at the William and Mary School of Law, said the Occupy movement is not merely a chance to be heard.

"It's an opportunity to be seen," he said, noting that "occupation" is the concept behind the movement.

Rep. Trey Gowdy, R-S.C., chairman of the subcommittee, said that the foundation behind NPS' decision to allow the protesters to stay in the park for months "is highly fragile." He added that it's unfair that the district is assuming all of the costs, including police and cleaning crews.

But Rep. Danny Davis, D-Ill., said he thought the protests were a First Amendment right that does not require congressional intervention, and added that he was "delighted" homeless people have joined the movement.

Citizens of a free country should not have to ask permission to occupy spaces, he said, adding that free speech must be protected not just for Occupiers, but for all citizens.

Issa said it's not a question of allowing people to protest. He noted that D.C. is the world's protest capital, and just the day before, March for Life protesters assembled by the thousands on the National Mall.

"Yesterday, we had the March for Life protesters. They came, they protested, and they left. Had they had stayed, they would have been expected to stay in hotel rooms," he said.

"Freedom is not an absence of uniform rules," he added.

Jarvis said he was sending one final warning to the group before U.S. Park Police begin enforcing the ban on camping in McPherson Square.

After the hearing, Jarvis clarified that enforcing the camping ban would not lead to a full-scale eviction of the encampment. Protesters, he said, are permitted to exercise their First Amendment rights in McPherson Square 24 hours a day.

Jarvis didn't address whether the camping ban would be enforced at a second, smaller Occupy-related encampment in nearby Freedom Plaza. Both areas just blocks from the White House.