With help from the U.S. Secret Service, Senate Sergeant-at-Arms Bill Pickle expects to file a report within a month on Judiciary Committee memos that Democrats contend were improperly taken from their computers and released to the media.

Pickle, a former top official in the Secret Service, brought in a handful of his former colleagues to lead the investigation, which began two months ago amid a firestorm surrounding the contentious issue of judicial nominations, according to the Sergeant-at-Arms office.

In addition to outside computer forensic experts from General Dynamics, the Secret Service and Capitol Police have now met with more than 60 staffers who might have some knowledge of the memos and the committee’s computer files, according to a Republican aide. It’s unclear where the probe is headed and whether it will result in the finding of any criminal wrongdoing or ethical breaches.

“They are making progress. They hope to conclude the investigation in the next three to four weeks,” said an aide to Pickle, who will forward a report to Judiciary Chairman Orrin Hatch (R-Utah) and Sen. Patrick Leahy (D-Vt.), the panel’s ranking member.

Pickle has been given a fairly free hand in the probe, but the decision to bring in the Secret Service — one of two federal agencies with oversight of computer crimes — was signed off on by Hatch, the Sergeant-at-Arms aide said.

“It will be a comprehensive report,” said the aide.

The agents are officially detailed to Pickle’s office, making them temporary Sergeant-at-Arms employees and helping to avoid a separation-of-powers issue in which the executive branch would be investigating legislative branch aides regarding their work. Presumably, if the investigators found criminal conduct, the files would be sent to the Justice Department.

While some staffers did have their own lawyers present during the questioning, it’s also unclear whether the investigation has focused on any particular aides.

A few days after asking Pickle to conduct the probe in mid-November, Hatch announced his own staff’s preliminary investigation had demonstrated that one of his committee aides and a former committee aide were involved with accessing the memos, which detailed how staff from Sens. Dick Durbin (D-Ill.) and Edward Kennedy (D-Mass.) met with outside liberal interest groups. At the meetings in 2001 and 2002, which were then summarized in internal memos, Democratic staff discussed strategies with the groups about blocking some of President Bush’s judicial nominees.

Hatch called the accessing of those memos an “improper, unethical and simply unacceptable breach.” He placed a staffer, whom he would not name, on administrative leave with pay.

That staffer was never reinstated and left the committee earlier this month, in a resignation that was planned before the Pickle probe began, a Republican aide said.

As for the second aide, Democrats were quick to point to Manuel Miranda, who worked for Hatch on the Judiciary Committee while the files were being accessed. Miranda is now Majority Leader Bill Frist’s (R-Tenn.) top adviser on judicial nominations.

Democrats have privately suspected Miranda’s involvement ever since Hatch fingered a “former staffer” of his being involved. In addition, the memos were placed on a conservative Web site and clearly had, on the last two of the 14 memos, his name spelled out on the electronic tagline of the pages.

Miranda declined to comment about the ongoing investigation.

Frist’s office said Miranda is “on leave,” his status since about the time the probe began. Frist aides would not explain the reasons for his leave, but a Republican aide said Miranda’s absence was not related to the Pickle investigation. His leave has been for family reasons, the aide said, describing his time off as “vacation leave.”

This aide said Miranda is expected back in the Frist office “within a couple weeks.”

Frist’s office declined to comment on the investigation Friday. “We’re cooperating with the investigation and we’ll have no further comment until the conclusion of the investigation,” said Amy Call, Frist’s spokeswoman.

Republican aides have said that there was no violation of any laws in obtaining the memos, that there was no “hacking” into the Democratic computers or any theft.

Some have called it a “glitch in the computer system” that put several files into something that a handful or more of both Democratic and Republican staff had access to, and that it was in those jointly shared files — under the heading of “My Network Places,” according to one GOP aide — where the Durbin and Kennedy memos were stored.

Since GOP aides contend the files were jointly shared, they say there was no crime. As one Republican aide put it, there were “several people who knew how to do it and certainly one person who did it a great deal.”

If that legal reasoning holds up, another critical question for Pickle will be whether disseminating those memos to the media violated Senate ethics rules and whether those memos could be considered confidential documents. That was a focus of the Senate’s investigation into the leak of Judiciary Committee documents regarding Anita Hill’s accusations of sexual harassment during Supreme Court Justice Clarence Thomas’ confirmation hearings in 1991.

If the memos aren’t considered illegally stolen and aren’t confidential, there may ultimately be no legal or ethical violations.

But Democrats, who are privately grumbling about the pace of the investigation, will be sure to put pressure on Republicans to fire any staff who took part in something that Hatch himself has already labeled “unethical.”

Neither Republicans nor Democrats appear to be receiving regular updates about the probe. Asked earlier this month if he’d heard anything from Pickle, Minority Leader Tom Daschle (D-S.D.) said, “It’s been since before the holidays.”

His staff said Friday there has been no recent update. Kennedy’s office has also not received any updates.

By pulling in outside help from General Dynamics and the Secret Service, however, Pickle is likely to avoid any charges that his investigation was tainted or not taken seriously.