Massachusetts Teen Accused of Urging Boyfriend to Commit Suicide Must Stand Trial

— -- It has been two years since a Massachusetts teenager allegedly urged her boyfriend to take his own life. Now, the state’s highest court is ordering her to stand trial in his death.

Conrad Roy III died of carbon monoxide poisoning in July 2014 after locking himself inside his truck in a Kmart parking lot in July 2014. At the time, prosecutors say, Roy was on the phone with his girlfriend Michelle Carter for 47 minutes. Carter, then 17, allegedly convinced him to stay in the vehicle after he had second thoughts.

“He was scared,” prosecutor MaryClare Flynn said. “She told him to get back in the car.”

In a series of text messages just days before, prosecutors say Carter was coercing Roy to kill himself. She allegedly wrote: “You need to stop thinking about this and just do it,” and, “There is no way you can fail. Tonight is the night. it’s now or never.”

Roy had been receiving treatment for mental health issues since 2011, according to court documents, which also say he attempted suicide in 2013 and was hospitalized before he met Carter.

Carter was indicted on Feb. 6, 2016, as a youthful offender on a charge of involuntary manslaughter, which makes her eligible for a sentence of up to 20 years in prison if convicted. Her defense attorney appealed to dismiss the charge, arguing that prosecutors failed to present the grand jury with sufficient evidence of manslaughter and that Carter’s conduct didn’t cause Roy to commit suicide.

But the Supreme Judicial Court in Massachusetts ruled Friday that a grand jury had probable cause to indict Carter on the charge, saying she engaged in a “systematic campaign of coercion” that targeted Roy’s insecurities and that her command to “get back in” during his final moments was a “direct causal link to his death.”

Carter, now 19, has been out on bail and barred from social media since 2015. She is expected to enter a plea July 21 at the first pretrial hearing in juvenile court.

Carter’s lawyer, Joseph Cataldo, said he’s confident his client will not be found guilty, arguing that her texts are free speech protected by the First Amendment. He called the case “a tragedy,” but said “it is not a crime.”

"I respectfully disagree with the Massachusetts Supreme Judicial Court's new and expansive definition of manslaughter. I believe it is in violation of the First Amendment. This case is a tragedy, but it is not a crime,” Cataldo told ABC News. “Michelle Carter did not cause Conrad Roy's death. It was his long time plan and his actions that brought about his own death, and I am confident the jury will conclude that she is not guilty.”

ABC News’ Linzie Janis, Doug Lantz, Jessica Hornig, Daisha Riley and Roger Lee contributed to this report.