Given the thousands of computers on Capitol Hill and the need to protect classified and confidential information processed on them, why is it necessary for Senate Sergeant-at-Arms Bill Pickle to call in executive branch experts to get to the bottom of the great Judiciary Committee memo pilferage dispute? Congress ought to be doing the probe itself.

As Roll Call reported last week, Pickle called in former colleagues from the Secret Service, where he once was a top official, to lead the investigation into what may have been a year-long Republican staff monitoring of Democratic strategy memos. The Boston Globe reported that the Republican staffers may have been exploiting a glitch in the committee computer system from the spring of 2002 to at least April 2003.

Leaked to conservative media outlets, the content of the memos was pretty shocking, indicating that Democrats delayed hearings on a nomination for the 6th U.S. Circuit Court of Appeals at the request of the NAACP to affect the outcome of an affirmative action case and sought to block the nomination of Bush nominee Miguel Estrada because he is Latino and might be hard to keep off the Supreme Court. Democrats deserve whatever criticism they receive for kowtowing to liberal interest groups.

But, content aside, Senators and their aides have a right to expect that the privacy of their internal communications will be protected — and the legislative branch ought to have the capacity to see that communications are secure. That includes the capacity to investigate compromises of security.

It remains to be seen whether GOP staffers’ reading of Democratic memos was illegal, a violation of Senate rules or just unethical. When he heard about it, Judiciary Chairman Orrin Hatch (R-Utah) pronounced himself “mortified at this improper, unethical and simply unacceptable breach of confidential files.” Such a statement suggests that, at a minimum, the GOP staffer responsible for the pilferage and leaking will be fired. A former Judiciary staffer widely named in the press, Manuel Miranda, is now on the staff of Senate Majority Leader Bill Frist (R-Tenn.).

The Globe said that Miranda denied the charges and added that “there appears to have been no hacking, no stealing and no violation of any Senate rule. Stealing assumes a property right and there is no property right to a government document. … These documents are not covered under the Senate disclosure rule because they are not official business and, to the extent they were, they were disclosed inadvertently by negligent (Democratic) staff.” GOP staffers claim that Democrats were warned that their memos were accessible and did nothing. Democrats deny it.

Pickle says he’ll get to the bottom of all this soon. We’re glad. There is a place for the executive in legislative leak investigations — as with the current FBI probe of highly classified intelligence on al Qaeda intercepts. But on internal matters, Congress ought not to have to call in executive agencies.