Wait on a sec, that gives the impression there was evidence that suggested he may have been guilty that DNA would have disproved, the actual lack of evidence is staggering, as this that I've obviously copied and pasted proves.
"Malkinson was identified by the victim in a
identity parade line-up, despite several key details not matching with the description of the perpetrator. For example, she described the attacker as being 3 inches shorter than Malkinson, with a hairless chest and no tattoos. Malkinson had chest hair and prominent tattoos on his forearms. She also said the attacker would have a "deep scratch" to his face, since she'd scratched him so hard she had broken one of her fingernails. Malkinson was seen at work the next day with no scratch to his face. He also didn't have the Bolton accent the victim said the attacker had.
[3]
There was no DNA evidence linking him to the crime at the time.
[7]"
The Police and prosecution services didn't charge him because they were unfortunate not to have the required advancements in DNA, they charged him because they were at best incompetent at worst corrupt.