The collapse of Dewey & LeBoeuf, once one of the biggest U.S. law firms, was due not to fraud by top executives but defections by its highest-earning partners, defense lawyers told jurors yesterday at the close of a criminal trial in New York, Reuters reported. Former Chairman Steven Davis, who helped build Dewey into a 1,000-lawyer firm before it went bankrupt in 2012 under a crushing debt burden, had no reason to believe the firm's books was false in any way, lawyer Elkan Abramowitz said in state court. Along with former executive director Stephen DiCarmine and former chief financial officer Joel Sanders, Davis faces dozens of counts including grand larceny, fraud and falsifying records. The most serious charge carries up to 25 years in prison. Over nearly four months of testimony, the office of Manhattan District Attorney Cyrus Vance has argued the three men directed subordinates to conceal the firm's teetering finances from lenders like Bank of America Corp and Citigroup Inc. through false accounting adjustments from 2008 to 2012. Dewey's bankruptcy was the largest in history for a U.S. law firm.