D.C. Attorney General Irvin Nathan said Wednesday that prosecutors are unlikely to pursue current or former District employees who collected less than $20,000 in unemployment benefits while on the city's payroll, meaning most of the 130 workers under investigation will probably avoid criminal sanctions.

"With respect to those that are the most egregious cases, we will definitely refer them to the U.S. attorney's office for prosecution," Nathan said. He later estimated the threshold for prosecution at $20,000, but said workers who stole less might still be targeted for criminal sanctions in some circumstances.

Earlier this week, Lisa Mallory, the director of D.C.'s Department of Employment Services, which administers the unemployment insurance program, said only some cases topped the $20,000 mark. Bill Miller, a spokesman for the U.S. attorney's office, which will decide whether to prosecute individual cases, did not respond to requests for comment.

Bad news, good news
> D.C. Mayor Vincent Gray said the city fell victim to unemployment benefit fraud because officials didn't have proper safeguards in place. "The controls were insufficient," Gray said at a news conference. But no more: District leaders say D.C. caught the 130 workers because of technology improvements, including access to a new database.

Nathan's remarks came days after District officials announced that in a sweeping crackdown, the city had placed 90 employees on administrative leave after an internal probe found they had likely committed unemployment insurance fraud. An additional 40 former employees also were implicated in the scheme.

Nathan acknowledged the number of workers suspected of fraud might climb as investigators continue their probe. "It could be considerably more," Nathan said.

City leaders are not waiting, though, to resolve cases. Some of the 90 current workers, Mallory said Wednesday, have already been fired, but she did not know an exact figure.

The scandal has ricocheted throughout government, ensnaring an aide to D.C. Council Chairman Kwame Brown and public employees at a hodgepodge of agencies.

Some of the worst alleged offenders, Nathan said, worked in the D.C. Public Schools, which employed six of the 10 employees accused of stealing the most from public coffers. A spokeswoman for the school system did not respond to a request for comment about the roles of the employees, but Nathan said most were bus drivers.

The University of the District of Columbia also employed two workers within the top 10.

But despite a concentration of alleged wrongdoing in some agencies, Nathan said investigators did not believe the scheme was organized.

"So far, the indication is that there is no ringleader, there is no collusion," Nathan said. "People recognized what they could do, and they unfortunately took advantage of it."

The individuals under investigation, Mallory said, all collected unemployment benefits for at least three weeks longer than legally permitted.

"These individuals were entitled to unemployment at one point. What happened is they did not get off unemployment at the appropriate time," Mallory said. "Any time after three weeks, we consider it fraud."

A mayoral spokesman said some employees who were placed on leave were being paid in accordance with labor agreements.