The state attorney general, defeated Tuesday in his bid to become the Republican nominee for US Senate, has been convicted at the tax fraud trial that he says cost him the election. "I haven't broken any laws," said Attorney General William J. Scott, the state's top prosecutor for more than a decade, who has a reputation as an anti-pollution crusader. "I have done nothing wrong. I have nothing to be ashamed of." He was found guilty of filing a false income tax return in 1972.