You asked — “I wonder if he sent it during that two hour period of time between the two shootings.”
I read that the package was received at the Post Office (where it was sent from) at 9:01 AM. Now we know one place that Cho went to in between times...
Regards,
Star Traveler
A flat package will still fit in a USPS box or if picked up from a dorm pickup box. Over amount of postage would ensure that it was delivered and not returned due to IP.
A over-sized package will not fit in a USPS box due to possible bombing or drug shipments and require a personal visit to the USPS or a box store. Metered postage at that point of sale will give the distance from the campus if is the case by way of tracking the metering machine by it's stamped number. The actual post mark may then might only come from the bulk center.