LOS ANGELES – Since the criminal trial of a top fund-raising official on Senator Clinton’s 2000 campaign began here nearly two weeks ago, a middle-age woman has been quietly perched on one of the wooden benches in the back of the courtroom. She jots down her observations in a small notebook and regularly consults with defense lawyers, but does not socialize with the handful of journalists covering the trial.

The unobtrusive and taciturn woman is the general counsel for Mrs. Clinton’s campaign, Carolyn Utrecht. She has served, it appears, as the senator’s eyes and ears in the courtroom as a parade of witnesses involved with an August 12, 2000, fund-raiser have marched in and out to recount their memories of the star-studded event.

On Friday, prosecutors rested their case against David Rosen, 38, who is accused of understating the costs of the gala in reports filed with the Federal Election Commission. Mr. Rosen, who could face up to 15 years in prison if convicted on the three pending felony counts, is expected to take the stand in his own defense when the trial resumes tomorrow.

Ms. Utrecht, 52, declined to be interviewed for this story. “It wouldn’t be appropriate,” she said as she left court Friday with a defense witness who was the chief architect of Mrs. Clinton’s campaign, Harold Ickes.

As the trial has unfolded, Ms. Utrecht has talked often with the lawyers representing Mr. Rosen, Paul Mark Sandler of Baltimore, Joseph Sandler of Washington, D.C., and Michael Doyen of Los Angeles.

Mr. Rosen’s lead lawyer, Paul Sandler, declined to comment yesterday on Ms. Utrecht’s involvement in the defense of the former campaign staffer.

In a statement issued after Mr. Rosen’s indictment was unsealed in January, the personal attorney for President Clinton and Mrs. Clinton, David Kendall, stressed that the campaign was assisting prosecutors. He did not mention any assistance to Mr. Rosen’s defense team. “The Senate campaign committee has fully cooperated with the investigation. Mr. Rosen worked hard for the campaign, and we trust that when all the facts are in, he will be cleared,” Mr. Kendall said at the time.

Asked yesterday about Ms. Utrecht’s role at the trial, Mr. Kendall declined to comment.

Mr. Kendall, who has not attended the trial, is well known as a result of his work defending Mr. Clinton against impeachment and a variety of independent counsel investigations.

Ms. Utrecht, on the other hand, is so low-profile that a reporter covering the Rosen case called her office in Washington twice recently without realizing that she was sitting at the opposite end of the same courtroom bench. She did not return the calls.

“She’s always been very discreet,” a Republican campaign finance lawyer who has known Ms. Utrecht for decades, Jan Baran, said. “She does not have a high public profile, but that’s intentional, and I think that serves both her and her clients well.”

Ms. Utrecht, who is a partner in a Washington, D.C., firm, Ryan, Phillips, Utrecht & MacKinnon, has strong ties to Democratic politics. She served as general counsel for Mr. Clinton’s campaign in 1996 and as a legal adviser to Vice President Gore in his 2000 presidential bid. She also advised the presidential campaign of Vice President Mondale in 1984 and the 1992 presidential primary bid by Senator Harkin of Iowa.

Between 1976 and 1983, Ms. Utrecht worked as a staff attorney at the Federal Election Commission.

Asked if Ms. Utrecht should be viewed as the Clintons’ personal representative at the trial, Mr. Baran said, “Oh, absolutely.”

Ms. Utrecht is outnumbered in the gallery by a more talkative contingent from a conservative legal watchdog group, Judicial Watch. At least three people from Judicial Watch, a group that helped press a related civil lawsuit against the Clintons, have been present throughout the criminal trial, intently recording the highlights of the proceedings on yellow legal pads.

One witness who drew special attention Friday was Mr. Ickes, the de facto manager of Mrs. Clinton’s 2000 campaign and a deputy White House chief of staff under Mr. Clinton. Testimony from Mr. Ickes about the campaign’s attitude toward large gifts of goods or services was at odds with that of three other witnesses involved in fund-raising for Mrs. Clinton’s Senate race.

Asked by the defense whether Mrs. Clinton’s campaign cared about the type of in-kind gifts that Mr. Rosen is accused of concealing, Mr. Ickes said, “No. As a general principle, no.” He later added, “Everything is relative.”

Asked if a fund raising event would be considered less successful if it took a lot of in-kind donations, Mr. Ickes said, “In lieu of cash, yes. If not in lieu of cash, no.”

The treasurer of the committee that staged the August 12, 2000, concert, Andrew Grossman, Mr. Rosen’s deputy on the campaign; Christopher Fickes, and a fund-raiser who described himself as a “dear friend” of Mr. Clinton, James Levin, all testified that they believed large in-kind gifts should be avoided because they could reduce the amount of cash Mrs. Clinton’s campaign would receive under a complex accounting procedure dictated by federal law.

Asked by a reporter about the differing testimony, Mr. Ickes acknowledged that very large in-kind gifts could have a negative financial impact, at least in theory. “All of these things are subject to a rule of reason. We didn’t pay for that and you had a tendency not to be very concerned about things you don’t pay for. If they were way out of proportion, that’s another question,” he said.

At that point, one of Mr. Rosen’s attorneys, Paul Sandler, appeared and cut short the interview, which took place in a courtroom hallway.

During Mr. Ickes’s testimony Friday, prosecutors tried to establish that his reputation as a conservative when it comes to campaign spending might have contributed to Mr. Rosen’s alleged decision to lie about the expenses for the concert, which featured Cher, Whoopi Goldberg, and Michael Bolton.

“I can squeeze the nickel,” Mr. Ickes said.

Prosecutor Peter Zeidenberg asked Mr. Ickes if he was “extreme” when it came to controlling costs. “I never look at myself as extreme in any regard, but I’m on the tighter side, if you will,” the veteran Democratic operative and attorney said.

The prosecutor had Mr. Ickes read from a memo he issued aimed at keeping the campaign’s costs down.

“Use messenger service only when absolutely necessary. Few things are needed the same day,” the memo advised. “Keep cost in mind when planning conference calls. Have an agenda for the call. Keep it tight.” The staff directive also said that cellular phone bills were too high and warned that “some cell phones may be pulled.”

Mr. Ickes spoke derisively about the guests and performers at the concert, describing them as “hoo-has.” He said his memories of the event were vague and unpleasant. “I went. It was hot. I wanted to get the hell out of there,” he said.