For Hynes, D.A. Since 1990, Publicity and Rivals Charles J. Hynes, 78, who is seeking his seventh term as Brooklyn district attorney, has used his longevity to his advantage, noting Brooklyn's 80 percent decrease in crime since he took office. Charles J. Hynes has been Brooklyn's district attorney longer than some of the law school students hoping to work for him have been alive. But as he began campaigning for a seventh term, he seemed unusually vulnerable. A steady stream of negative publicity surrounding his office, including concerns about his political connections and revelations about a series of wrongful convictions that occurred under his watch, stirred speculation that this year would bring about one of the rarest New York City political spectacles: a district attorney voted out of office. And yet Mr. Hynes has appeared increasingly confident on the campaign trail, racking up endorsements, trumpeting his accomplishments and offering well-honed rejoinders to the criticisms. And, at 78, he has used his longevity to his advantage, frequently noting Brooklyn's 80 percent decrease in crime since he took office in 1990. "We're in a campaign so people can say all they want," he said of his opponents recently. But they've got to prove it. The two former prosecutors challenging him in the Sept. 10 Democratic primary - Kenneth P. Thompson, a former federal prosecutor, and Abe George, a former assistant district attorney in Manhattan - have so far struggled to capitalize on his apparent vulnerabilities. Despite their success at fund-raising, they have struggled to build traction; some suggest that Mr. Thompson and Mr. George will divide the votes of those who have misgivings about Mr. Hynes, making it easier for him to win a primary that would all but guarantee him the post in heavily Democratic Brooklyn. Still, both are repeatedly focusing on what they view as an Achilles" heel - a series of wrongful convictions in cases where, critics say, prosecutors used drug-addled or unreliable witnesses to win convictions, sometimes going to extremes by threatening them or detaining them against their will. At least 50 homicide convictions involving the same detective are being reviewed by the district attorney's office. How did that happen on his watch? Mr. Thompson asked. Criticism of Mr. Hynes has also focused on what critics have long argued is his willingness to use his office for political ends, rewarding supporters and punishing opponents. A well-known example, opponents say, was his policy of refusing to release the names of ultra-Orthodox Jewish defendants accused of sex crimes, which drew praise from some rabbis who have been among his most reliable supporters. The policy was sharply criticized by victims" groups and sex-crime experts, who said it fostered a culture of secrecy that made it harder to curb abuse. At a raucous candidates" forum on Monday night, Mr. George accused him of "protecting pedophiles." Mr. Hynes has his answers at the ready. Troubled witnesses go with the territory of prosecuting street crime, he suggested, and whenever a compromised witness is discovered, "my kids," as he calls his staff members, work to exonerate those who were convicted. His office has denied threatening or detaining witnesses. The agreement with the Hasidim, he argued, prevented shunning of victims as informers in that close-knit community and should be evaluated in the context of his many successful prosecutions of sexual abuse cases. But both his rivals have found themselves on the defensive, both about qualifications and the efficiency of their campaigns. Mr. Thompson, who is African-American, was the lawyer for Nafissatou Diallo, the hotel housekeeper who accused Dominique Strauss-Kahn, then managing director of the International Monetary Fund, of sexual assault. While Mr. Thompson ultimately won her a civil settlement, the criminal charges against Mr. Strauss-Kahn were dropped because of questions about her credibility; prosecutors criticized Mr. Thompson's handling of the case, also finding him too eager to put himself in the spotlight. Mr. Thompson was also the lawyer for two senior state senators, John L. Sampson and Pedro Espada Jr., in an investigation of efforts to operate a casino at Aqueduct racetrack. The two senators were later charged with corruption. Mr. George, 34, the son of immigrants from India, is a political novice with no management experience. Though he has some high-profile contributors, he has a small paid staff and handles reporters" calls himself, on his cellphone. He has portrayed his inexperience as a virtue. "I'm the only real outsider in this race," Mr. George said at the candidates" forum. If you want to stop political corruption, you have to look for a guy outside the machine. Mr. Hynes, a graduate of St. John's University Law School, was a prosecutor in Brooklyn in the late 1960s and 1970s, holding top positions in the district attorney's office he now runs. In 1975, Gov. Hugh L. Carey raised his profile by appointing him a special state prosecutor to investigate operators of shoddy, abusive nursing homes that were exploiting Medicaid. He was New York City's fire commissioner from 1980 to 1982 and Gov. Mario M. Cuomo named him a special state prosecutor for the city's criminal justice system in 1985. In the latter role, he obtained convictions against three white men in the killing of a black teenager in Howard Beach, Queens. Among the highlights of his career as Brooklyn's district attorney were the convictions of a former Brooklyn Democratic leader, Clarence Norman Jr., for extortion, and of two judges for taking bribes. Nate Schweber contributed reporting.