The DA doesn't even have the case yet.
Not "officially" perhaps, however, the last news report provides somewhat of a differing viewpoint:
"Some of the processing includes not only lab work, but taking the
results of the investigation and
having it prepared in a courtroom presentation format."
and:
"Box stated they are able to obtain this data from known information and sometimes through the collection and interpretation of data from the vehicle's computer.
"These results of the data are currently being complied in a computer-generated
courtroom presentation format," said Box."
http://www.stategazette.com/story/1889980.html
September 2, 2012 article
Now maybe I'm off base on these comments, but I've never seen a Sheriff department anywhere that prepares cases for "courtroom presentation". That type of work is done by the attorney's or their staff as a general rule.
I also recall Sheriff Box referring a reporter to the DA's office when they wanted answers to questions about the case. I'm not sure what article that was from, but I am certain I did read that. So why would the Sheriff deflect questions to the DA if the DA wasn't handling the case?
All JMO
ETA: At this stage of the case, it appears they have their POI (one person), so the investigation is pretty much wrapped up except for the evidence they are waiting on to come back from the lab, (and where, pray tell, is this "lab" that takes a year to process evidence?), but regardless, they know who did this, IMO, so why no arrest? Incompetent DA? Big, scary, high-profile defense lawyer? None of this makes sense. There is NO reason that anyone should just be out walking the streets so a few i's can get dotted or a few more t's can be put into "courtroom presentation" format. That is BS!!