If I recall correctly, about six months prior VA Tech had a fugitive scare on campus. The fugitive was an escaped inmate armed with a sheriff's gun which was used to kill two people, a hospital security employee and another sheriff. The fugitive was William Morva, already held for murder.
That was about six months prior to the VA tech massacre. They had to hide and hope for the best missing class that day. The response by some of the student body after being reminded how vulnerable they were was to demand the ability to defend themselves be re-instated. Many people on campus actualy did have a CCW. I believe at least one of the victims of the VA tech massacre did as well.
However the head official came out and reminded everyone of the strict no tolerance weapon policy, and that anyone violating that would expelled, likely ruining thier academic career.
We all know what happened six months after that.
That said there was only a law on the books in VA against weapons in k-12. The only prohibition on weapons on the VA Tech campus came from the campus policies themselves.
Thier own rules even state that anyone found with a firearm or weapon will be asked to remove it( from person, dorm etc), and failure to comply will result in action/arrest. So merely possessing it unknown would have according to thier policy not been grounds for immediate disciplinary action, just the lawful request that it be removed from the premises.
Now asking a person once might be interpreted by them to mean forever, but legaly the person would only be breaking tresspassing laws on that specific occasion by remaining, and could leave and return at a future date if they still remained an enrolled student or employee. So if they were a registered student or an employee and complied that day and returned armed at a future date they would not be in violation of tresspassing until asked to leave once again.
What I am getting at is they have no legal backing in making someone remove a weapon, just a policy. They however do have a legal right to determine who is and is not on thier property.
So once they are allowed to come back they could do so with a firearm legaly because they are no longer tresspassing.
However the campus police may not feel the same way and charge the individual with tresspassing just for possessing the firearm. Unless they asked them to leave on that specific incident and they did not comply however I do not believe they would have legal grounds for that charge. They would still probably have to deal with it in court though.
That is from a legal standpoint.
The administration can decide to just expell the student whenever they want.
So legaly a person could, and can still carry thier CCW weapon on campus (in Virginia), and if nobody knows, and they are not asked to leave, they will be breaking no laws. Most just chose not to risk it prior to the VA Tech shooting and potentialy ruin thier career by being expelled. Also obviously only those students over 21 would be capable of having a CCW permit to begin with. However it is my understanding that VA Tech had a pretty decent percent of older individuals as students returning from the military or going back to school for a career change. So combined with the rest of the student body and the employees a lot of people were over 21.