Prosecutors today tightened the investigative noose around Michael Abell, a former top Justice Department official who is charged with conspiring to launder money and obstruct justice, when Donald Ferguson, a former assistant U.S. attorney in Miami, pleaded guilty and agreed to cooperate with investigators. Ferguson and Abell are among 59 people charged with engaging in illegal activities in support ofColombia's Cali cocaine cartel. "This is clearly a victory for the prosecution," says TIME's Cathy Booth. "Nobody knows yet what Abell is going to do, but Ferguson is the fourth defendant in a row to plead guilty, putting up no fight." Among the charges to which Ferguson pleaded guilty: he delivered $75,000 in Cali drug profits to the wife of a drug defendant held in a Miami jail.