I hope they waited on DNA before making this arrest.
Something still just feels slightly off to me right now...
(And yes we have seen recent cases where they arrested without DNA and DNA proved the person innocent.)
This is just totally JMO...but I think they were in fact waiting for DNA. They were very quick to say that there was no threat to the community. I personally think it will come out they thought it was him from the beginning, and watched him until the DNA came back. I read in an article (I will try and find it now and update with a link) that he deleted his facebook profile before he was arrested. I think he knew they knew.