I take it this is the same situation about which there is another posting. Everybody involved in this business could face very serious criminal charges. Under the circumstances as you describe them, murder is probably not one of those charges. But an imaginative and aggressive prosecutor might figure out a way to give it a try. If that happens the charge must be taken very seriously, even if it seems like a stretch.
This sad scenario is happening more and more in this age of the internet. Can the 3 go to jail? Maybe but unlikely. The person who filmed could be punished more harshly, but not necessarily. This scenarios getting more and more common because of Facebook.
Bottom line: There is no good answer here, except that if someone close to you has participated, take down any posts immediately and if anyone comes around asking, get to a lawyer right away. Kids need to recognize that anyone on the net is basically out there forever.
Only an experienced criminal defense lawyer can properly advise the persons involved and answer your questions.
Bullying is a hot topic in criminal law. Be aware and beware.
Of course, every answer is based on the question asked and requires a more complete context. This answer should not be relied upon to make a legal decision. Seek the advice of an experienced criminal defense attorney before acting. Law Offices of Raymond G. Wigell, Ltd. Defenders of the Constitution since 1975/ Aggressive Creative Defense Strategies/ Website: www.waaltd.com 24/7 --(708) 481-4800.