'Such unusual circumstances': Here's what Michelle Carter's appeal hinges on

EDITOR'S NOTE: The text messages printed in this story contain graphic language, which some readers may find disturbing.

BOSTON - Attorneys for the woman convicted of manslaughter in her boyfriend's suicide challenged the law that convicted her before Massachusetts' Supreme Judicial Court Thursday.

The case, which saw the law of involuntary manslaughter applied to suicide, could potentially set a new precedent for the way the law is applied to speech.

Michelle Carter told her friends she “heard him die,” according to court documents.

That’s part of the evidence Judge Lawrence Moniz used to convict Michelle Carter of involuntary manslaughter in the death of her boyfriend, Conrad Roy III.

Judge Moniz explained his decision to Carter in open court last year, mentioning a few legal precedents used to hold her responsible for Roy’s death. But it was the evidence contained in text messages between Carter and her friends that he said was what ultimately condemned her -- in his opinion.

Two months after Roy died of carbon monoxide poisoning from sitting in his truck with a running motor pump, Carter sent a text message to a friend explaining she believed herself to be responsible for his death.

“His death is my fault like honestly I could have stopped him I was on the phone with him and he got out of the car because it was working and he got scared and I fucking told him to get back in,” Carter wrote on Sept. 15, 2014.

Both the prosecuting attorneys and Judge Moniz pointed to that statement as the moment Carter became responsible for Roy’s death.

That decisions is being challenged by Carter's appellate attorneys, who say this application of the law of involuntary manslaughter 'unlawfully penalizes protected speech' and 'invites arbitrary enforcement'.

"Carter is the first person ever convicted, anywhere, in such unusual circumstances," her attorneys argued in their appellate brief submitted to the SJC. "If this Court affirms, Massachusetts would be the only state to uphold an involuntary manslaughter conviction where an absent defendant, with words alone, encouraged another person to commit suicide."

MORE: Michelle Carter guilty of involuntary manslaughter in boyfriend's suicide

As Moniz explained in court, Roy had conducted extensive research on his own, bought the generator and parked his truck. But according to Carter’s text, Roy got out of the truck when he started to sense the carbon monoxide poisoning.

"He literally sought fresh air," Judge Moniz said, referring to Roy's previously unsuccessful attempts to commit suicide. Moniz said Roy had shown a pattern of choosing to live rather than follow through.

If Carter’s text is to be believed, she was on the phone with him when he died, meaning she knew what was happening to him and, in Moniz’s opinion, should have done something to stop him.

“Miss Carter knows – by her own admission – that Mr. Roy has followed her instructions,” Moniz said. “As she indicates in various text messages subsequently created to some of her friends, she indicates that she can hear him coughing and she can hear the loud noise of the motor.”

Moniz explained he couldn’t lean solely on one instance of Carter’s testimony and cited a number of other messages sent to other friends.

“The court notes that I looked for independent corroboration of some of the statements that Miss Carter made to make sure that there was no undue reliance on any one source of evidence,” said Moniz.

In text messages dated around July 12 – the date of Roy’s suicide – Carter tells other friends she spoke with him on the phone and may have known what was going on. Messages between Carter and Roy indicate she indeed knew what he was doing.

“He called me and I heard like muffled sounds and some type of motor running and it was like that for 20 mins and he wouldn't answer. I think he killed himself,” Carter said in a message to a friend.

It was a series of messages like that, which Moniz used to convict her of manslaughter -- a decision that has been criticized by free speech advocates.

But the big question -- of whether or not a person can legally cause the suicide of another -- has already been asked and answered.

The SJC ruled on that when it first allowed her case to go to trial.

“The big question has already been answered and the question now is whether this set of facts is enough for that finding,” Suffolk University Law Professor Rosanna Cavallaro said.

Professor Cavallaro explained the indictment was upheld by the SJC, signifying the possiblity that another person could legally cause the suicide of another person.

She says this appeal will be dependent largely on whether or not the prosecutors on Carter's case proved that she was legally responsible for Roy's death.

MORE: All the texts between Michelle Carter and Conrad Roy the day he died

The ACLU's Massachusetts chapter said in a statement at the time, the conviction "exceeds the limits of our criminal laws and violates free speech protections guaranteed by the Massachusetts and U.S. Constitutions."

Legal experts have argued the case could set a precedent in the digital age for holding people responsible for crimes simply by the things they say.

Moniz, however, cited a precedent set in a 2001 case, Commonwealth v Levesque, in which a couple was found responsible for the deaths of six firefighters because they failed to report a fire. When firefighters were told there may be people inside a cold storage warehouse in Worcester, they went inside and were killed in the blaze.

Judge Moniz pointed to Carter’s “failure to act,” alongside her statements urging Roy to follow through with his planned suicide.

Carter's case will be heard by the SJC Thursday, Oct. 4 beginning at 9 a.m.

You can stream the arguments here.

Message sent 9/15/14 8:24 p.m. to Friend #4:
His death is my fault like honestly I could have stopped him I was on the phone with him and he got out of the car because it was working and he got scared and I fucking told him to get back in *** because I knew he would do it all over again the next day and I couldnt have him live the way he was living anymore I couldnt do it I wouldnt let him. And therapy didnt help him and I wanted him to go to McLean with me when I went but he would go in the other department for his issues but he didnt wanna go because he said nothing they would do or say would help him or change the way he feels. So I like started giving up because nothing I did was helping and but I should of tried harder like I should of did more and its all my fault because I could of stopped him but I fucking didnt all I had to say was I love you dont do this one more time and hed still be here and he told me he would give me signs to know he is watching over me but I havent seen any and I just idk I'm sorry about this rant I just needed to get that off my chest and its finally all sinking in

Text messages sent to and from Michelle Carter on the day of Roy's death

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