A federal official behind the firing of U.S. Park Police Chief Teresa C. Chambers testified yesterday that the chief's troubles began months before she went public with concerns about staffing and money.

Donald Murphy, deputy director of the National Park Service, told an administrative law judge that Chambers had flouted agency protocols and failed to follow orders from superiors before the comments that led to her suspension in December. Chambers never was permitted to return to work and was fired in July.

Chambers has asked the U.S. Merit Systems Protection Board to overturn her ouster, contending that she was illegally removed for speaking out about issues affecting public safety. Yesterday, an administrative law judge began hearing testimony from Murphy and other key players in the dispute.

Nearly a year before the blowup over her comments to The Washington Post and other news organizations, Chambers was reprimanded for taking her police vehicle home, not allowed by the Park Police but a privilege common in many jurisdictions where commanders are expected to be on call around the clock.

According to testimony yesterday, when one of her top aides was tapped for a temporary assignment at the Park Service, Chambers, who had expressed reservations about the move, took her complaints to the second-in-command at the Interior Department, Deputy Secretary James Steven Griles, and managed to have the transfer canceled.

The charges Murphy eventually lodged against Chambers, from engaging in unauthorized lobbying to disregarding the chain of command, "represent overall a pattern of not listening and not following my instructions," Murphy told the court.

He was the first witness in a hearing before Judge Elizabeth B. Bogle that could stretch for four days. The board hears appeals by federal employees challenging job actions.

The board is Chambers's latest hope for regaining the job she held for 22 months. The 27-year law enforcement veteran has been out of work since Dec. 5, soon after she complained that the region's parks and parkways were growing more dangerous because of staffing and budget pressures.

Seated between her attorneys with her laptop in front of her, Chambers worked through the hearing, writing notes to her lead attorney, Mick Harrison, and selecting documents from stacks of files and binders.

Officials have said they fired Chambers because she disclosed sensitive security and budget information and improperly lobbied Congress.

During several hours of testimony, the lawyers representing the Park Service and Chambers characterized the chief's conduct very differently.

Through his questions, Robert D. L'Heureux, representing the Park Service, portrayed Chambers as chronically overstepping the bounds of her job. Harrison depicted her as a concerned employee determined to do what was best for her force of 620 officers and the community they serve.

To prevail, Chambers and her attorneys will have to prove that the firing cannot be justified by either the law or the circumstances.

Chambers also could win reinstatement if the judge finds she was retaliated against for being a whistle-blower.

The core mission of the Park Police is patrolling the Mall, the capital's other national parks and area parkways.

Since Sept. 11, 2001, the agency has had new demands placed on it, particularly in securing prominent landmarks such as the Washington Monument and Jefferson Memorial.

A national study of the Park Police had recommended a more streamlined mission, focusing more on security and less on criminal investigation and traffic enforcement.

Chambers wanted to add hundreds of officers so the force could meet its new responsibilities along with its old ones.

Chambers, a Maryland native who was a Prince George's County police commander and then police chief in Durham, N.C., before becoming the first woman and the first outsider to lead the Park Police, took her concerns to the press and to Congress.

Murphy testified that the chief's campaign jeopardized the safety of the community and upset relations with those funding the Park Service in Congress. Conversations that Chambers had with a senior aide on the appropriations subcommittee for the Interior Department were particularly problematic, Murphy said.

When the aide, Deborah Weatherly, took the stand yesterday, she said she was concerned by the conflicting messages she was hearing about the state of the Park Police and about the pace of planned reforms.

However, she said that she did not find it inappropriate or unusual that Chambers had reached out to the subcommittee.

"We get contacted dozens of times a week," she said.

Teresa C. Chambers is challenging her firing as U.S. Park Police chief.