For weeks, the headlines have been full of investigations of top District government officials. Much of the investigating has been done by three men in the government, and their findings have become very public, indeed.

But who are the investigators themselves? The District Weekly has prepared profiles of the three who have been involved in the investigations of Mayor Washington and human resources director Joseph P. Yeldell. The following is the third in a series.

Auditors, says David Legge, an auditor, "in general, I think, are, to some degree, people who, in most cases, I would say, have to be a little, you know, careful."

Not careful in the sense of doing neat, presentable work. Every auditor has mastered that. To David Legge, the District government's chief internal auditor, careful means never having to say you're sorry.

There are plenty of chances, particularly when one's job is to analyze how the city spends its funds and whether it is getting full value from them.

One can comment on policy - and end up being sorry. One can try to rewrite policy - same result. One can comment on the general state of District government finance - and be very sorry.

So David Legge does very little of these, at least not publicly. He has been the city's chief money analyst for 11 years, across three different forms of government, and all he is willing to say is that "things are better than everyone says they are."

Such care has elevated Legge to a $39,000-a-year position as the nuts-and-bolts man who probably has as much impact as, but less visibility than, any department head in the city's executive branch.

In December, after three other tries, it was Legge to whom Mayor Walter E. Washington turned for a full report on the hiring of Joseph Yeldell's wife Gladys as a D.C. government GS-9. Legge's report was issued early this month.

In 1976, Legge was asked to step in and straighten out money management trouble at the board of elections and ethics and the office of consumer affairs. He did so.

In 1975, it was Legge who identified and recommended a solution for several cases of misuse of funds at D.C. Village, the city's home for the indigent elderly.

"Our job's not limited to identifying problems, or criticizing," said Legge, in an interview at his eighth-floor office at 415 12th St. NW. "We should offer solutions."

Legge has a staff of 30 to help in that effort, 27 of them professionals. The annual budget of his office, formally christened the office of municipal audit and inspection, is about $700,000, with another $70,000 in federal grant funds thrown in.

The office's workload is long in inspections and surprisingly short on formal audits.

Legge and his staff do not, for example, do a full audit of the entire city budget. That is left to the city's independent auditor, Matthew S. Watson, and to the General Accounting Office, which compiles an audit each year for the House and Senate District Committees.

A typical task for his office, Legge said, is to study a departmental or sub-departmental budget, problem or product. Such work is almost always assigned, Legge said, either by the mayor or by a department head, the only people who have the authority to press his office into service.

Legge, whose name is pronounced "leg," grew up in Fairfax, Va., the son of farmers. He is a graduate of Fairfax High School and Strayer College, and has been an auditor for the city since 1954. He was promoted to his present position in December, 1965.

Legge, 48, a heavy-set, graying man, began his career with the Commerce Department's Coast and Geodetic Survey. He was a distributor of nautical and aviation maps and charts at first, then an accountant in the same section. He is married and the father of four children - sons 24, 21 and 8, and a daughter, 5.

Legge is well aware that the District has been the butt of many jokes - and even more inquiries - on the subject of money. He sees the problem as one of priorities within departments. "It's hard to make accounting systems the top priority at the expense of a program that delivers a service," he said.

Legge refused to characterize the state of the city's finances, even though he was asked to do so twice. He did take issue, however, with a characterization offered in June by Arthur Andersen & Co., an independent auditor hired by the Senate District Committee. Andersen found the city's finances in a mess, and said it could not even conduct an audit for two years, much less improve matters, because the city's records and figures were hopelessly inaccurate.

"The things that they reported are probably things that needed to be reported," Legge said. "They'll get greater attention, especially in Congress.

"But I wouldn't use the term 'mess.' Improvements have been needed. We've reported some of it before. Others have as well."

The city has two large, recurring financial problems, Legge said: It runs out of money for basic services, and it is structured in many ways like a federal agency, even though it is a city.

Legge regards both problems as largely inevitable. He prefers to look at the long-run future.

"Our role is to look for the effectiveness of controls on programs. Is there good internal control that gives various levels of management the information sufficient to manage programs? We're not just looking at numbers and figures," Legge said.

How well has his office done? "Well enough," Legge said. The last GAO assessment of his office found that "we're doing quite well," Legge said.

Legge's office performs two audits every year: of the D.C. Armory and RFK Stadium, and of the city's uncollected taxes. Every third year, rotating with his counterparts in Maryland and Virginia, Legge audits the Washington Metropolitan Area Transit Commission. At any one time, Legge said, his office is involved in "nine or ten" projects.

"What we do is recommend always," Legge said, "We don't order anything to do anything." Does that prove frustrating? "At times," Legge said. He admits that he might easily try to influence policy by seeking or using the press, "but I never strive for publicity.I don't think it would make us more effective."

In the future, Legge hopes his office can help "get the District all the revenue that's possible." Given that "we have nothing to do with (setting) tax rates, anything we can do to maximize revenues, we'll do," Legge said.

"We've been working quite some time, the District has, to improve," Legge said. "This is a large complex organization . . . We as internal auditors here have the responsibility to provide a constructive service for the Mayor and other high officials."

As for recommending changes, said David Legge, auditor, "well, we've got to be careful."