It has been 20 years since Scott Peterson was convicted for the murder of his wife and unborn child, but he is hoping further DNA testing of evidence could win him a retrial — an event a former California prosecutor called “unlikely” to happen, RadarOnline.com can reveal. In an order recently filed, a judge mandated DNA testing on a 15.5-inch piece of duct tape recovered from Laci Peterson’s pants during her April 13, 2003, autopsy, Front Page Detectives reported. The test on the tape will be conducted by Pure Gold Forensics, Inc., along with more than a dozen physical pieces of evidence for w…