(FORTUNE Magazine) – The scandal on Wall Street broadened significantly when Boyd L. Jefferies, 56, admitted criminal violations of securities laws. He also settled civil charges by the Securities and Exchange Commission without admitting guilt, agreeing to leave the securities business for at least five years, among other penalties. His is the first major case since the scandal broke last spring that does not involve charges of insider trading. It confirms that federal investigators are casting their net far wider than was previously known. Jefferies is the Feds' biggest fish since Ivan Boesky. His Jefferies & Co. investment firm in Los Angeles is a major trader of large blocks of stock and has played an important role in many recent takeovers. Jefferies has done business with such well-known raiders as Carl Icahn, Irwin Jacobs, and Saul Steinberg. The SEC charges that Jefferies bought and agreed to sell back to Boesky, without profit or loss, stock in companies including G.D. Searle and Cooper Laboratories. The deal enabled Boesky's firm to own more stock than SEC capital requirements allowed. The SEC also charges Jefferies with manipulating the market at the request of an unnamed person. Irwin Jacobs says in Jefferies's defense, ''Everyone else who has been charged has had personal gain. He's the only one who hasn't made money off of his violations.'' Jefferies isn't accused of profiting from his actions. He was apparently building the business of his holding company, Jefferies Group, of which he owns 13%. Jefferies is the newest link in the chain that began when Dennis Levine gave evidence leading to Boesky. Investigators say Boesky's singing led to Jefferies, who, as part of his arrangement with the authorities, is joining the chorus. The new development will surely heat up indignation already bubbling in Congress. Now the states are considering ways to slow the pace of takeovers. In mid-March the National Association of Attorneys General unanimously approved guidelines for states to use in determining whether mergers within industries should be challenged. Though some states have takeover laws, the guidelines could be used by all states and are tougher than the federal government's. States also may sue under federal antitrust laws. That gives a state attorney general plenty of ways to gum up the works of a deal even if his state does not have applicable antitrust laws. Of the 50 state AGs, 31 are Democrats, including Robert Abrams, the New York attorney general and chief architect of the guidelines. He expects more states to file suits to block mergers.