The Guardian has a timeline
here. In December of 2009, "A meeting log confirms the forensic scientist on the case recommends that Y-STR testing, which isolates the male chromosome (as commissioned by Malkinson’s lawyers a decade later), could be done to get a clearer result but the CPS advises against it."
Another
article from The Guardian stated, "Malkinson’s conviction was overturned when DNA samples from the victim’s clothing, which had been preserved in a forensic archive, were tested and found to contain DNA from someone who was likely to have been the attacker. This breakthrough was almost missed as the victim’s vest top, bra, knickers and other clothing were destroyed by GMP, despite a preservation order being in place."
Bill Robertson
stated that, "According to APPEAL, the new DNA breakthrough was only possible because samples had been retained in a forensic archive which the CCRC had neglected to search. Crucial exhibits were lost or destroyed by Greater Manchester Police, despite the force having a strict legal duty to retain them, meaning they were not available to be tested." The archiving of case material is a major issue in this essay.