The former chief fiscal officer of the D.C. Department of Employment Services was sentenced yesterday in U.S. District Court here to six months in prison and a $3,000 fine for her role in a $6,000 purchasing fraud scheme.

U.S. District Judge Charles R. Richey, who gave two codefendants substantially stiffer sentences on Thursday, said he was showing leniency to Crystal J. Willis, 32, because she had cooperated fully with prosecutors.

Assistant U.S. Attorney Daniel J. Bernstein said in court that as a result of Willis' cooperation with the FBI, "information she supplied has led to other investigations of other individuals."

Bernstein said he could not elaborate on the "other investigations."

On Thursday, Richey sentenced Dwayne E. Moore, 38, a former department supervisor, to 20 months to five years in prison and a $10,000 fine in connection with the fraud scheme.

An independent department contractor, Clarence B. Wade Jr., 31, of New York City, was sentenced by Richey to 56 months to 14 years in prison and also fined $10,000.

Moore and Wade were taken into custody immediately after sentencing. But Richey yesterday released Willis until next Friday "to get your affairs in order."

In addition to the prison term and fine, Richey sentenced Willis to perform 200 hours of community service and imposed a three-year probation period. The specific prison sentence was one to three years, with all but six months suspended.

"There is a public policy that corruption by public officials should be punished, because this defendant and the others have breached their sacred public trust," Richey said.

"On the other hand, there is a strong public policy, present in this case, that favors cooperation and immediate disclosure of wrongdoing.

"People of this community who do in fact go astray, or may be tempted to do so, should realize they should do what this defendant has done -- namely, report their activity to the appropriate officials."

Willis told Richey she realized "I've made a terrible mistake . . . I'm terribly sorry, very sorry. It will never happen again."

Willis, Wade and Moore pleaded guilty earlier to using city funds to purchase about $4,000 in chandeliers, lamps and other electrical fixtures for their personal use.

The purchases were made with checks authorized by Willis as chief fiscal officer of the department, according to the government's evidence.

Prosecutors contended in court papers on Thursday that purchasing fraud is "a situation all too pervasive in the agencies of the District of Columbia." That allegation was immediately denied by angry city officials.