I Guess I'm Unclear....

The News says that every single one of the bullets found at the Newtown CT School Massacre, along with everything the bullets hit such as desks, will be forensically investigated as "evidence".  Also, every single survivor child who "saw something" is going to be interviewed, again for forensic "evidence"
 
I can understand the obvious comfiscation of Lanza's computers and such, and investigating his home as a crime scene, but what on earth is there to gain by the prolonged (and costly) investigation of "every bullet", and re-living the horror for each of those precious children?  We already know who did it, how he did it, where he did it, when he did it, how he got there, how he got in, etc.... all we're really missing is WHY he did it.... and I highly doubt the bullets, the desks, and the children will answer THAT question.
 
I'm unclear.
 
Any thoughts?

I suppose so.  But they already have all 3 guns he brought in, the shotgun he left in the car, and know that they were registered to his mother....

Maybe one of the children heard him say something.  I hope the investigation is worth it, because it is truly horrifying.

The crime scene was 100% certainly photographed. Not sure about video taped though.

You would think that everything would be recorded in classrooms by the school now days the way things are with kid diddlers and such.

I know if I was a school teach in this day and age, I sure as hell would want everything recorded for my own protection.