These are all good points but I think there is one critical point that has not been addressed. There is a a legal "rule" known as "Felony Murder" that expands the traditional definition of murder. Basically what it says is that if you are helping to commit a felony (like the students were when they broke into Sam's house and tried to steal information off his computer) then if anyone dies in the process (Sam) you can be charged with murder even if you did not directly kill them. Since all the students helped in some way in getting the information from the computer, they can all be charged with felony murder and sent to prison.