For anyone who works in a school, what would be the penalty for a student who broke into a teacher's office and was caught snooping on the teacher's computer?

Suppose after the student snooped the computer no longer worked, and the next day a computer virus spread through the whole school.

And, finally, suppose the principal suspected, but could not prove, that said student had pulled the fire alarm to gain access to the office in the first place.

For the first action, I have been told that the penalty ranges from simply calling the parents to one-week suspension, and everyone I talked to seemed anxious to convince me that they would be careful to prove a student's involvement before issuing any sort of punishment. Still, I can't help wondering if that was an official line given to me as a parent. Realistically, would the accumulation of circumstantial evidence make the punishment harsher? If so, how much harsher? Please help.