In July 2014, Michelle Carter’s 18-year-old boyfriend took his own life in a Kmart parking lot.

After his death, Carter texted a friend.

"Like, honestly I could have stopped it," she wrote.

But instead of trying to stop her teenage boyfriend from taking his life, prosecutors in Massachusetts believe that Carter pressured Conrad Roy III to go through with the act.

And on Friday, the state’s highest court ruled that she could go to trial for her alleged role in his death.

"I hope they hold her accountable for her actions," Roy’s grandfather, Conrad Roy Sr., told the Boston Globe. "She told him to get back in the truck. She prodded him on. All of the text messages are pretty much self-explanatory."

The Supreme Judicial Court’s ruling — which found that a grand jury was justified in returning an indictment in Carter’s case — was unanimous, the Associated Press reported. Justice Robert Cordy wrote:

"We conclude that, on the evidence presented to the grand jury, the verbal conduct at issue was sufficient and, because a conviction of involuntary manslaughter is punishable by imprisonment in State prison and inherently involves the infliction of serious bodily harm, the grand jury properly returned an indictment under the youthful offender statute."

Carter, who was 17 at the time of Roy’s death, faces a charge of involuntary manslaughter.

"We appreciate the court’s thorough review of the law as it pertains to the facts of this case, and it’s decision to uphold the juvenile court’s denial of the defendant’s motion to dismiss,” Gregg Miliote, spokesman for the Bristol County District Attorney’s office, said in a statement. “We will now focus our efforts on preparing for the upcoming trial in this case."

Prosecutors have alleged that Carter pressured Roy to go through with suicide, counseled him on his fears and researched suicide methods. Text messages between the two propelled the case into a national spotlight and highlighted Carter’s alleged role.

"I mean, you’re about to die"

For more than a week in July 2014, Carter and Roy exchanged hundreds of messages in which Carter insisted that Roy would be better off dead.

"You’re finally going to be happy in heaven. No more pain," she told him in one message. "It’s okay to be scared and it’s normal. I mean, you’re about to die."

According to prosecutors, the two had struck up a romantic relationship — mostly online — in 2012. Her attorney says they had met only a few times in person over the course of two years prior to Roy’s death.

Roy had a history of depression and had attempted suicide in the past, but his family was hopeful that he would get through it.

“He seemed to be pulling out of it,” his grandmother Janice Roy told WBZ.

Text messages recovered by police, however, suggest that by 2014, Carter had tired of Roy’s idle talk of suicide and wanted him to go through with it — now.

“You always say you’re gonna do it, but you never do,” Carter complained. “I just want to make sure tonight is the real thing.”

Another time, she texted: “You can’t keep pushing it off, though. That’s all you keep doing.”

Carter was insistent, even when Roy steered the topic to other things:

ROY: How was your day?

CARTER: When are you doing it?

Roy said he was having a good day, but Carter wasn’t satisfied.

CARTER: Really?

ROY: Yes.

CARTER: That’s great. What did you do?

ROY: Ended up going to work for a little bit and then just looked stuff up.

CARTER: When are you gonna do it? Stop ignoring the question???

Roy had doubts and was scared, according to his texts. What if it didn’t work and he ended up injured for the rest of his life? How would his family cope with the loss?

Carter had answers.

He would be her guardian angel in heaven.

She would comfort his family, and they would move on.

If he followed the directions he had found online for killing himself with carbon monoxide, it would “100 percent work,” she said.

“There isn’t anything anyone can do to save you, not even yourself,” she told him.

The day of Roy’s death — July 12, 2014 — he and Carter exchanged texts in the early morning hours.

“You can’t think about it. You just have to do it,” Carter said, telling him she didn’t understand why he was hesitating.

“I’m gonna eventually,” he replied. “I really don’t know what I’m waiting for but I have everything lined up.”

She suggested that he take medication to fall asleep and allow the fumes to work.

She worried that he wouldn’t go through with it because the sun would soon be coming up.

She suggested that he go to an empty parking lot.

They texted throughout the day about the plans, about Roy’s doubts and about Carter’s insistence that “the time is right” and that he was ready.

The day before his death, she told her friend: “I’m thankful that our last words were I love you.”

At some point on the night of July 12, Roy went through with the suicide. He died of carbon monoxide poisoning inside the cab of his pickup truck.

While he was in the truck, he was on the phone texting and talking with Carter, she told her friend.

“Like, honestly I could have stopped it,” Carter texted Samantha months later. “I was on the phone with him and he got out of the car” because the carbon monoxide was working, she said. She added that she “told him to get back in.”

Roy had a history of depression and had previously attempted suicide. Details of his struggles with mental health were presented to the grand jury, according to the ruling; Roy had been receiving treatment since 2011, according to the filing, and attempted suicide in 2013 by trying to overdose on acetaminophen.

“A friend saved his life by contacting emergency services,” they note.

Court documents note a conversation that took place weeks before Roy’s death, weeks before Carter was pushing him to take his own life:

ROY: we should be like Romeo and Juliet at the end

CARTER: Haha. I’d love to be your Juliet :)

ROY: but do you know what happens in the end

CARTER: “OH YEAH F— NO! WE ARE NOT DYING”

Days later but still weeks before Roy’s suicide, Carter urged him to get help:

CARTER: But the mental hospital would help you. I know you don’t think it would but I’m telling you, if you give them a chance, they can save your life

CARTER: Part of me wants you to try something and fail just so you can go get help

ROY: It doesn’t help. trust me

CARTER: So what are you gonna do then? Keep being all talk and no action and everyday go thru saying how badly you want to kill yourself? Or are you gonna try to get better?

ROY: I can’t get better I already made my decision.

But in the days leading up to Roy’s death, Carter’s tone seemed to have changed.

She was the one brainstorming ideas with Roy on how he should kill himself, according to prosecutors, but she feared that Roy would make up an “excuse” to explain why it wouldn't work.

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"You always seem to have an excuse," she texted him.

When Roy decided to use a generator, Carter was impatient.

“Do you have the generator?” she asked him.

“Not yet LOL,” he replied.

“WELL WHEN ARE YOU GETTING IT?” she wrote.

Eventually, Roy did find a generator — his father’s — but it was broken. Carter told him to take it to Sears for repairs, and suggested alternatives.

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Roy’s body was found by police the morning of 13 July.

Dana Curhan, an attorney for Carter’s appeal, said he had argued that Carter’s words alone were not enough to constitute manslaughter. Instead, he said, it had to be “words plus” — words plus a threat, or words plus intimidation.

"This is not what we were hoping for,” he told The Washington Post in a phone interview. “I have not seen any case in Massachusetts where somebody was charged with manslaughter based on words alone.”

A message left for another of Carter’s attorneys, Joseph Cataldo, was not immediately returned Friday.

"They still have to prove manslaughter beyond a reasonable doubt,” Curhan said. “And that may be a much harder thing for them to do."

Looking at all the evidence, the court decided that “there was probable cause to show that the coercive quality of the defendant’s verbal conduct overwhelmed whatever willpower the eighteen year old victim had to cope with his depression, and that but for the defendant’s admonishments, pressure, and instructions, the victim would not have gotten back into the truck and poisoned himself to death,” Cordy wrote in his statement.

“Consequently, the evidence before the grand jury was sufficient for a finding of probable cause that the defendant, by wanton or reckless conduct, caused the victim’s death.”

Abby Phillip contributed to this report.