Looking at the timeline a little more closely … these reports say that detectives only spoke to DJK for the first time about a week before he was arrested ... and only days before he contacted them and evidently put himself squarely on their radar! He was arrested 8th October. Maybe speaking with local businesses about DJK made them think he wasn’t that much of a suspect initially? He was quiet, he was working that night, that was the way he walked home.
“Detectives first spoke with Kelsall about a week before he was arrested and charged with murder ….
However, while detectives were continuing with their murder investigation, and before they were in a position to speak with Kelsall a second time, it will be alleged he contacted them with other details of what took place that night.”
http://www.heraldsun.com.au/news/ac...ad-his-last-beer/story-fnii5s3y-1226739920271
"The Daily Telegraph can reveal that Kelsall had already been interviewed by police, days before he contacted them to say he had engaged in sexual activity with Huxley the night of the fatal stabbing."
http://www.dailytelegraph.com.au/ne...ad-his-last-beer/story-fni0cx12-1226739920271
So that is probably why they didn't have his DNA before ... they hadn't spoken to him yet. And even when they did speak with him, they didn't regard him seriously enough to ask for DNA? Or he refused?