Maybe because there wasn’t anyone to pursue, and they thought they might have greater success interviewing witnesses and trying to find out who the guy was and where he might be headed. How on earth can you pursue someone if you don’t know who they are or where they went. Obviously you are not thinking rationally here. Barney Fife would jump in his car and start driving around aimlessly. Law enforcement officials try to gather as much info as possible before acting.
Pray for W and Va Tech