Congress scored a signal — and deserved — victory this month when a three-judge federal appeals court ruled that the Justice Department acted unconstitutionally when it raided the Rayburn Building office of Rep. William Jefferson (D-La.) in 2006.

At the same time, the ruling creates an imperative for Congressional leaders and executive branch officials to work out procedures that will meet court muster in case it’s ever necessary in the future for the FBI to gain access to a Member’s office.

The D.C. Circuit Court did not declare that the Constitution’s Speech or Debate Clause puts all legislative territory off-limits to criminal searches, but a failure to establish agreed procedures for searches might have the practical effect of causing police agencies never to contemplate another raid. Members under suspicion of law-breaking might well think that their offices would be a safe place to stash incriminating evidence.

The appeals court ruled that the Justice Department erred in failing to give Jefferson an opportunity to safeguard strictly legislative papers when the FBI conducted its 18-hour search of his office to look for evidence to bolster its case that the Congressman solicited and took bribes to promote business activities in several West African nations.

It’s not clear that the Justice Department needed to conduct the raid — the first in U.S. history at a Congressional office — in as much as it had sworn statements from former Jefferson aides about his alleged activities and had recovered $90,000 in cash stored in his home freezer.

At the time it happened, the raid struck us — and Members of both parties, as well — as yet another case of the Bush administration’s penchant for overexertion of executive authority. We’re pleased that the circuit court unanimously agreed. Now, we trust, executive overkill will not jeopardize the government’s case against Jefferson, which is set for trial in January.

Jefferson’s lawyer, Robert Trout, is expected to challenge any evidence gained from the FBI raid as tainted by the illegal search even though the court ruled that non-legislative materials collected in the raid did not need to be returned to the Congressman.

Whatever the ruling’s effects on the Jefferson case, it’s important that Congress and the Justice Department work out procedures for handling future cases. A good starting point for the process would be an amicus brief submitted to the appeals court by former Rep. Abner Mikva (D-Ill.), who also served as chief judge of the U.S. Court of Appeals for the District of Columbia and as White House counsel under President Bill Clinton.

Mikva urged that “minimum standards” for future seizures should include advance notice to the appropriate chamber of Congress that a raid is contemplated; an opportunity for the Member to screen out protected legislative documents; and procedures for a court to judge disputes over contested documents.

As the Mikva brief points out, the Australian Parliament and attorney general negotiated a memorandum of understanding on the issue in 2005 that Congress and the Bush administration could use as a model. We urge Speaker Nancy Pelosi (D-Calif.), Senate Majority Leader Harry Reid (D-Nev.) and Attorney General Alberto Gonzales to put aside their many other differences long enough to assign aides to a task force and begin negotiating a similar agreement.