How could a young person -- who was a close friend of the deceased, Conrad Roy, 18 -- allegedly do such a horrifying thing? And what are the legal ramifications of what a teen says online or in a text?
But a lesser discussed point this tragic story raises is how quickly a teen can go from normal everyday life to facing severe, life-altering legal consequences.
"To me this is the unrecognized area that parents, particularly parents of teens, miss all the time," said Green during a recent interview at CNN's studios.
"So many of our friends have armies of tutors, extracurricular activities, all sorts of angles covered ... but when it comes to the law, there's this black hole."
Green, a journalist, lawyer and television legal analyst, says people often think of the law as scary and intimidating and believe they don't need to worry about it because their kid is never going to get into legal trouble.
Whether it's a case as serious as Carter's involuntary manslaughter charge, or a simple allegation of vandalism, parents need to be prepared, Green said.
"I cannot count the number of kids I know, good kids, who find themselves in the wrong place at the wrong time," said Green.
"I have now two young adults, and when they were going through their teenage years, it was a simple matter of a party that went wrong, a group of kids in the park when the police stop by and have some questions, bringing something to school they shouldn't have.
"And in each of those cases, a little bit of knowledge of the law, a little bit of knowledge of what their rights are, the right way to behave, would have saved parents a heck of a lot of grief."
Green thinks parents should think about the issue in the same way they would track down a good orthopedist if their child breaks a bone, or the best tutor if their child is struggling before the SAT.
"I am not saying that parents need to go out and get their own law degrees ... but just dipping your finger into the topic will help you understand what's available to you to help you parent better," she said.
The importance of legal advice in the digital age
She gives some real-life examples especially in the social media age. For instance, what if a teen is asked by a school administrator to turn over his or her cell phone based on allegations the teen was sending inappropriate texts?
What parents should know, Green said, is that a school can't open a cell phone for no reason at all.
"They need to have reasonable suspicion that something's wrong," said Green, who said parents would be wise to talk to their teens about what's appropriate and what's not when it comes to handling such requests from school officials.
"If you're asked, as a child, for a locker search, to open a phone, to open a laptop, if it's your property, pause and ask if you could call Mom and Dad," she said.
"We can act whether we're lawyers or not as that first line of defense."
Green also says that parents of college-bound teens should spend a few minutes looking online at the school's code of conduct.
"They don't tell you about it during that fantastic tour with the kid walking backwards as your child is looking around to say, 'Who can I party with?' But it's a really important set of information because different schools have different levels of tolerance" for activities such as drinking on campus, she said.
The legal stakes for parents too
And even before teens head off to college, parents should know about social host laws, where parents could be held criminally responsible or face civil damages if teens drink alcohol in their home and then go off and do something inappropriate or even tragic.
More than 150 cities or counties and 24 states currently have such laws on their books, according to Mothers Against Drunk Driving.
In some cases, parents can be held liable even if they didn't know the drinking was taking place.
"It doesn't have to be you with the shaker, like an episode of 'Mad Men,' serving up Manhattans to a group of grateful teens," said Green.
"If you've made it possible in your home, if you don't lock your liquor cabinet -- I never did -- and all of a sudden kids are drinking, that could be a problem as well."
While Green is passionate about educating parents on why they need to think about the law, she stresses that bad behavior by teens still needs to be punished either legally or at home.
"I am not advocating that kids should be absolved of responsibility. If a kid does something wrong, if they broke the law, they ought to be punished appropriately by it. But we also live in a society where we have legal rights, and I want parents to know that they should be aware of what those are so they can help their child use better judgment."
How to shop for a good criminal defense lawyer
So if after reading this, you are moved to try to find a criminal defense lawyer, how on earth do you go about finding one?
Green's advice is to ask friends and colleagues for referrals and also consult with your state bar association, since you would want someone in your state who has experience with criminal defense issues.
Then she says you should call up and interview a few lawyers, asking them everything from how much their services would cost (that can vary), to who would handle the work, to what their philosophy is about the law and teens' rights.
"You may or may not end up being friends afterwards, but that's not as important as feeling secure that your lawyer is approaching the situation in a way that feels right for you."
Do you think it's important for parents of teens to be aware of the law and their children's legal rights? Share your thoughts with Kelly Wallace (@kellywallacetv) on Twitter or CNN Living on Facebook