The police still have the evidence, detective notes, et all from Kathy's murder. I would bet whatever evidence was collected for Wanda June, they have it.
Pat Postligone, who is quoted in one article, went through a lot of old files and read them/organized them/tried to solve them. He's retired now, but if he was talking about Wanda June to the media, he worked on her case years after it was originally worked.
To clarify, I don't mean to say the files were disorganized before because I have no reason to think this.