The school shooting...was the matted grass...tarot card and casing.
Intersting though...they are using bloodhounds and are walking areas along frontage roads, where there is brush and trees...this doesn't look like an investigation that is LOOKING for vehicles...I think the sniper shoots from trees/underbrush and then has the "time" to get to a get away vehicle...I think the cops may be wasting time on the all evasive "white van"...
Remember the BIG FLAP in DC about "video cameras" at all the street intersections...I think the sniper has a very good sense about "security devices" and has a good sense to avoid these devices...it will be a "candid camera" that catches this freak...
This is the site I took a look at Saturday afternoon, and to which I observed you would have a clear line of sight to shoot from on the roof and upper stories of the Ramada Inn three or four blocks north of the site. The fact that a police dog alerted for gunpowder at that church wall need not mean that the shot that killed Charlot came from there.
The police have not been releasing info about the trajectory of the snipers' shots. They may be able to tell from what height the shots came. Charlot was shot in the neck. I think it would be easier to hit him there if you were shooting from above.