BOSTON (CBS) – The Massachusetts Supreme Judicial Court ruled on Friday that a Plainville teen can stand trial for involuntary manslaughter after prosecutors say she convinced her boyfriend to follow through with his suicide attempt.

Eighteen-year-old Conrad Roy’s body was found in his pickup truck in Fairhaven in July 2014. He died of carbon monoxide poisoning.

READ MORE: 'My Daughter Doesn't Feel Safe': Parents, Teachers Raise Concerns About Violence At Lawrence High School

Police found Michelle Carter, who was 17 at the time, had sent dozens of text messages to Roy, encouraging him to kill himself.

Conrad Roy. (Photo credit: Janice Roy)

Conrad Roy. (Photo credit: Janice Roy)

Carter’s lawyer argued last year that her messages to Roy were free speech protected by the First Amendment.

On Friday, the state’s highest court ruled that the case should proceed and that a grand jury properly indicted Carter.

“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,” the SJC said in its ruling.

READ MORE: How Colin Powell Made An Impact In Massachusetts

No trial date has been set.

The Bristol County District Attorney’s office released a statement on the court’s decision. District Attorney Thomas Quinn has recused himself from the case due to extended family connections with Roy’s relatives.

“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,” Director of Communications Gregg Miliote said. “We will now focus our efforts on preparing for the upcoming trial in this case.”

Michelle Carter’s attorneys said they are “surprised” by the ruling, and that Carter is “disappointed.”

Cheryle Tavares-Merritt, a friend of Roy’s mother, said the ruling is an important one to make sure similar incidents don’t happen in the future.

“I was wishing it wouldn’t go the other way, because in my opinion that person should be held liable for their actions that led to this young man’s suicide,” she said.

MORE NEWS: 'Haitian People Are Suffering': Be Like Brit Foundation President Responds To Missionary Kidnappings

WBZ NewsRadio 1030’s Carl Stevens reports