TRENTON, N.J. - By following the money defendants raise to post bail, New Jersey prosecutors hope they've found a powerful weapon to help them crack down on violent street gangs. Long a fixture of federal courts, bail source hearings have not been widely used by New Jersey prosecutors since they were approved by lawmakers almost three years ago. The hearings have yet to be used in state prosecutions, according to the attorney general. The hearings require defendants to prove that the money they post to a bond agency - typically 10 percent of the bail set by a judge - did not come from illegal sources such as theft, or from the sale of weapons or drugs. The usefulness of bail source hearings is about to be tested in a Trenton courtroom. On Monday, a Superior Court judge in Mercer County has scheduled a hearing that will require Bernard Green, also known as "Petey Black," to divulge the source of the money posted toward his $750,000 bail.