A prosecutor says a woman accused of sending texts encouraging her boyfriend, 18, to kill himself used him "as a pawn in her sick game".
Michelle Carter is charged in the 2014 death of 18-year-old Conrad Roy III who was found dead of carbon monoxide poisoning in his pickup truck in Fairhaven in July 2014.
Prosecutors say that the 20-year-old had persuaded Roy to kill himself in calculated a bid to get "attention" as the grieving girlfriend, the Daily Mail reports.
"She used Conrad as a pawn in her sick game of life and death,' said prosecutor Maryclare Flynn.
They added that on July 10, two days before his suicide, she had carried out a "dry run".
"She knew her plan to get attention would work because she pre-tested it," they said.
"Two days before Conrad committed suicide, she did a dry run, texting several girls that Conrad had gone missing while simultaneously testing Conrad, telling him to get the gas machine."
The court heard that Carter sent 40 text messages to Roy urging him to kill himself before he finally took his own life.
"She put him in the car that night," Flynn added.
Carter, who appeared in court in a salmon pink jacket on Tuesday, had then played the grieving girlfriend, even organising a baseball tournament in his memory - but hosted it in Plainville - her hometown not Roy's, the court heard.
Roy's best friend Thomas Gammell asked her to move the memorial game but she had refused.
Texts they exchanged about the game revealed she wanted to ensure she got credit for the baseball tournament.
"Ok awesome thank you! You're not taking credit for my idea, right?" she text him.
Defense attorney Joseph Cataldo said Roy previously was suicidal and Carter had talked him out of taking his life.
He said today that Roy was seriously depressed over the divorce of his parents and a victim of physical abuse by a relative who was on a "path to take his own life for years".
He added that Carter was not responsible for his death.
"This is a suicide case," he said, 'not a not a homicide."
Roy's mother Lynn Roy, who broke down in tears during her testimony, also took the stand, telling Taunton Trial Court about her son's struggle with depression.
She said he had social anxiety and had been having 'bad thoughts'.
Lynn Roy said that on the night he died, she and he son had taken a walk along the beach, laughing, joking and talking 'about life'.
"You think your kids are doing better," Roy said, alluding to her son's previous suicide attempt.
Gammell later took the stand, saying that he had never even heard of Carter until Roy's death.
Carter waived her right to a jury, meaning the judge will hear the testimony and issue the verdict.
Prosecutors released transcripts of text messages the then-17-year-old Carter sent to Roy. In one, she allegedly wrote: "The time is right and you're ready, you just need to do it!"
The court heard that Carter and Roy exchanged more than 20,000 text messages - with more than 1000 of those messages sent in the days leading up to Roy's death.
Prosecutors say Carter sent her boyfriend dozens of text messages urging him to take his own life.
Carter's lawyer argue that she tried repeatedly to talk him out of it and only began to support the plan when it became clear he would not change his mind.
They add that the texts are protected under free speech and that Roy was depressed and previously tried to take his own life.
Carter was 17 when Roy took his own life via carbon monoxide poisoning and prosecutors argue she is criminally responsible because she encouraged him to kill himself in a series of text messages.
In some exchanges, she even revealed she was frustrated he had not taken his life yet.
"Well... I guess [that I am frustrated] just because you always say you are gonna do it but you don't,' she text him. 'But last night I know you really wanted to do it and I'm not mad. Well, I mean, kind of, I guess, just because you always say you're gonna do it... but you don't but last night I knew you really wanted to and I'm not mad."
When he mentioned he was worried it would hurt his family, Carter told him they'd 'get over it".
"Everyone will be sad for a while but they will get over it and move on. They won't be in depression. I won't let that happen. They know how sad you are, and they know that you are doing this to be happy and I think they will understand and accept it. They will always carry you in their hearts."
Others she badgered him whether he was going to "do it today", adding in another exchange "tonight is the night. It's now or never".
In another text, Roy told her he was 'gonna do it today' to which she replied 'You promise?'
In the hour before his death, prosecutors say, he was on the phone with Carter for 47 minutes, at one point telling her he was getting out of the truck because he feared it wasn't working.
"The car was filling up, and he was scared," said prosecutor Flynn. "She told him to get back in the car.'
"When he actually started to carry out the act, he got scared again and exited his truck, but instead of telling him to stay out of the truck... Carter told him to 'get back in'," the police report said.
Days before the suicide, prosecutors say Carter wrote, "Don't be scared. You're finally to be happy in Heaven."
"When are you going to do it? Stop ignoring the question???? You can't keep push [sic] it off," prosecutors claimed Carter texted Roy.
"It's inconceivable," said Claudette Roy-Viaol, Roy's great aunt to ABC News. "I just don't understand how someone could do that, to encourage someone they claimed to love."
Roy had also attempted suicide and had been hospitalised before he met Carter.
In a text message sent two weeks before his suicide, he wrote of his desire to end his own life. "I can't get better,' he wrote. "I already made my decision."
Roy's body was found in the truck in Fairhaven, Massachusetts on July 13, 2014, after his parents reported him missing, and police found the text messages after looking through his phone.
Police found a gasoline-operate water pump in the back seat of the truck after he died. A coroner later ruled he died of carbon monoxide poisoning.
Carter messaged one of her friends nearly a week later expressing her fears that her messages to Roy had been found, People reported.
"I just got off the phone with Conrad's mum about 20 mins ago and she told me that detectives had to come and go through his things and stuff," she wrote.
"They read my messages with him I'm done... His family will hate me and I could go to jail."
The case involving Carter has drawn national attention after transcripts of those text messages were made public.
Even though Carter, who met Roy while on a vacation to Florida several years earlier, reportedly called herself his 'girlfriend', his friends and family said they never knew of the relationship.
Carter had also repeatedly posted online about how much she missed him, saying at one point, "I will never understand why this had to happen."
In March, a controversial psychiatrist said Carter was 'involuntarily intoxicated' by prescribed antidepressants when she texted her boyfriend encouragement as he committed suicide.
Psychiatrist Dr Peter Breggin testified that Carter was not responsible because she was being treated with the antidepressant Celexa in 2014, which would have altered her brain and meant she wouldn't have understood the impact of her texts to Roy.
"She had no notion of wrongfulness on what she was doing," Dr Breggin told the court, according to 12WPRI.
Dr Breggin, who was hired by defence attorneys, said Carter loved Roy but experienced a metamorphosis due to her medication.
"The impairment of being on the drugs while you are growing up - while you're brain is maturing, while your frontal lobes are developing - you're talking about being inundated with neurotoxic effects," he said.
Prosecutors criticised Dr Breggin's credentials during cross-examination and sought to discredit him as an "extremist" who was critical of antidepressants.
Assistant District Attorney Katie Rayburn pushed Dr Breggin to admit he only reached his conclusion about Carter based on medical records and the text exchange between her and Roy.
The judge did not rule on whether Dr Breggin can testify but the psychiatrist has been previously banned from testifying in other cases.
Carter's defence team were granted a request late last year for funds to hire an expert to examine the antidepressant she was taking at the time.
Her attorney Joseph Cataldo said at the time the drug Celexa could be the key to her defence because it can increase suicidal thoughts.
Where to get help:
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• Samaritans 0800 726 666
• If it is an emergency and you feel like you or someone else is at risk, call 111.