Legislators Using Law As Shield In Probes

· The bribery case against Rep. William J. Jefferson (D-La.) has been stalled for more than two years after FBI agents raided his congressional office, largely because of fights over whether investigators exceeded their authority. A federal appeals court in the District has already barred prosecutors from using information gathered in the raid. The case now hinges on $90,000 in cash found in the lawmaker's freezer, which the government contends was bribes from telecommunications companies. Jefferson is fighting the allegations.

· Long-running investigations of Rep. John T. Doolittle (R-Calif.) and former House majority leader Tom DeLay (R-Tex.) and their connection to disgraced lobbyist Jack Abramoff have slowed to a crawl because of debates about the scope of the speech or debate clause.

· The top lawyer for the House last year cited the legal protection in his successful attempt to quash a subpoena to appropriations panel staff member Greg Lankler. Prosecutors sought Lankler's testimony in their investigation of a lobbying firm's ties to Rep. Jerry Lewis (R-Calif.).

Legal experts say that lawmakers' aggressive use of the clause poses problems for the Justice Department's public integrity section. Earlier this year, prosecutors unsuccessfully sought to persuade the Supreme Court to overturn the ruling in the Jefferson case, saying that if the lower-court decision persisted, it would call "vital investigative techniques into immediate and serious question."

The Renzi prosecution will test those boundaries. Once a rising GOP star and a protege of Sen. John McCain (R-Ariz.), Renzi announced he would not run for reelection amid the intensifying investigation of a land-swap deal that he helped broker. Instead, he is channeling his energy to fight a 35-count indictment handed down in February. Last week, he asked a judge to dismiss charges against him or, at a minimum, to exclude taped conversations and critical testimony from his assistants that may have been obtained in violation of the speech or debate protections.

Brian Heberlig and Kelly Kramer, Renzi's attorneys, said that investigators had improperly snooped on "hundreds of phone calls between Renzi and his legislative aides and 16 phone calls between Renzi and other members of Congress."

The exchanges included a call involving the entire Republican conference days after the 2006 midterm elections, a chat between Renzi and Rep. Jack Kingston (R-Ga.) about their votes for House GOP leadership candidates and another conversation between Renzi and Rep. John Shadegg (R-Ariz.) about election results and the performance of the National Republican Congressional Committee.

"The volume of protected legislative acts seized during the wiretap is staggering," the defense lawyers wrote.

Wyn Hornbuckle, a spokesman for the U.S. attorney in Arizona, who is leading the Renzi case, said prosecutors will "reserve comment" on Renzi's arguments until filing a formal response next month.

In a memo prepared by government lawyers before the wiretaps in October 2006, prosecutors contended that constitutional restrictions would not apply because the eavesdropping would occur while Congress was out of session. They planned for a special team to review evidence touching on legislative activity, but made an exception for talk related to the land swap.