By Dave Wedge Wednesday, June 2, 2004 Brockton authorities are probing an alleged junior high prostitution racket, including whether to charge a 13-year-old girl accused of pressuring her mentally impaired friend into turning tricks for as little as $5. Brockton School Superintendent Joseph Bage said the disturbing case that has rocked West Junior High School is being investigated by Brockton police and Plymouth District Attorney TimothyCruz's office. Bage said no disciplinary action has been taken against either girl because the incidents allegedly occurred behind a shopping plaza a half-mile from the school. ``Once they're away from the school building, they're...