The Brooklyn assemblyman who briefly lost his seat over an ethics violation said voters should not hold that against him as he runs for Congress.

Roger Green, who is challenging a fellow Democrat, the 12-term incumbent Edolphus Towns, in Brooklyn’s 10th Congressional District, said his 2004 guilty plea for accepting $3,000 in fraudulent travel reimbursements should not count as a liability in his race for Congress.

Mr. Green said that, like Clarence Norman, the former Brooklyn Democratic county chairman who was recently acquitted of a similar charge, he would have won his case had it gone to trial. He said all members of state legislatures and Congress should be required to take an ethics course at least once in a two-year term.

“That should be a requirement,” Mr. Green said in an interview with The New York Sun. “Members of the bar are required to attend classes on professional conduct and ethics. We make the laws and we’re not.”

Mr. Green, 54, is waging an uphill battle to unseat Mr. Towns, 71. Mr. Green argues that he will represent the residents of the district, which includes Brooklyn Heights, Bedford-Stuyvesant, and Canarsie, more effectively than Mr. Towns. Both men were elected to their current seats in 1981.

Also running against Mr. Towns in the September primary are City Council Member Charles Barron and a hip-hop journalist and community activist, Kevin Powell. All three challengers have raised questions about Mr. Towns’s support for the Central American Free Trade Agreement, which they say exports American jobs, and accuse him of missing several key votes in Congress.

Mr. Green, who has represented the neighborhoods of Fort Greene, Clinton Hill, Park Slope, and Bedford-Stuyvesant in the Assembly, resigned his seat on June 1, 2004, over the ethics charges, but successfully ran for re-election later that year.

In retrospect, Mr. Green said, he was unaware that what he was doing was wrong. “None of it was clear,” Mr. Green said, referring to the Assembly rules regarding travel reimbursements. “And I think I was validated three weeks ago when Clarence went into court on the same issue and all he did was he showed the jury the travel guidelines, and they said he’s innocent.”

A spokesman for the state Assembly said state lawmakers are reimbursed $143 a day of travel to and from the state capital. Mr. Green acknowledged he accepted the reimbursement while taking rides arranged by a company doing business with the state.

Mr. Green said other local politicians with similar problems rarely are questioned about them. When asked, Mr. Green, who is black, said he is the victim of a racial double-standard.

“I actually do. I don’t think I’m being paranoid about it. We made a lot of progress, no doubt about it, but there is a residue of systemic racism in the criminal justice system,” he said.

“My attorneys told me that if we went to trial in Brooklyn, there was no way that the prosecutors could get a conviction. But in Albany, with the makeup of the jury, a different culture, a different perception,” a conviction seemed more likely, Mr. Green said.

During a television interview last week, Mr. Green said the president of Brooklyn, Marty Markowitz, who is white, is no longer asked about his misdemeanor.

In 1998, Mr. Markowitz, then a state senator, pleaded guilty to misstating the source of $25,000 in campaign funds raised during a bid for the presidency of Brooklyn.

“Marty gets re-elected as a state senator and there was this much written about it,” Mr. Green said, making a zero with his index finger and thumb. “No story afterwards.”

Another example of a double standard, Mr. Green said, was the case of an upstate assemblywoman, Susan John, chairwoman of the Substance Abuse and Alcoholism Committee. Ms. John was arrested in Albany in 1997 for driving under the influence of alcohol and now heads the Assembly’s Labor Committee, and, according to Mr. Green, is rarely questioned about the incident.

Other colleagues are not as lucky. State Senator Ada Smith of Queens pleaded not guilty this week to attacking a former aide. Last week, Ms. Smith was stripped of her $9,500 annual stipend and the use of a car provided by the Democratic Party because of her “consistent pattern of inappropriate behavior.”