Revenue collected by the Manhattan district attorney’s office has increased by 40% in fiscal year 2007 versus 2006, and Manhattan’s murder rate has been cut nearly in half this year, the district attorney, Robert Morgenthau, announced yesterday. The office in 2007 returned $43 million to the city and state from revenues collected through criminal fines, forfeitures, and back taxes, and it has received nearly all of the $105 million in imposed fines from the convictions of two former chief executives of the manufacturing and services company Tyco International. The money, $10,000 of which is outstanding, will be calculated into the 2008 fiscal year once the case goes through its final appeal early next year, the chief assistant district attorney for Manhattan, James Kindler, said.