EAST TAUNTON, Massachusetts - A Massachusetts woman who sent her boyfriend numerous text messages encouraging him to kill himself when they were teenagers was found guilty of involuntary manslaughter. 

Michelle Carter, now 20, was charged in the death of 17-year-old Conrad Roy III in July 2014. Roy's body was found inside his pickup truck sitting in a store parking lot full of carbon monoxide. Prosecutors said, when he left the truck, Carter instructed him to "get back in," which eventually caused his death. 

Juvenile Court Judge Lawrence Moniz decided the case since Carter waived her right to a jury trial. 

Carter's lawyer claimed Roy had a history of depression and suicide attempts and that he was determined to take his own life. However, although Roy took "significant actions of his own" to take his life, Carter's demand to get back in the truck constituted wanton and reckless conduct, according to the judge. She knew he was in the truck, yet failed to call police or his family. 

"She called no one and finally she did not issue a simple additional instruction -- get out of the truck," Moniz said.

According to the prosecutors, her text messages supported their original claim that Carter caused Roy's death by "wantonly and recklessly" aiding in his death. They allege Carter pushed the topic of suicide because she was desperate for attention from her peers, reported by CBS Boston. 

Judge Moniz set Carter's sentencing for August 3. He ruled that Carter can remain free on bail but ordered she stay in the state and not to make contact with any of Roy's family. She faces a sentence that can range from probation to 20 years in prison.

Carter and Roy met in Florida in 2012 while visiting relatives. Their relationship largely consisted of text messages and emails.

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

Her texts later became more insistent after Roy appeared to delay his plan.

"I thought you wanted to do this. The time is right and you're ready __ just do it babe," she wrote.

In another text sent the day Roy died, Carter wrote: "You can't think about it. You just have to do it. You said you were gonna do it. Like I don't get why you aren't."    

Roy, 18, had a history of depression and had attempted suicide in 2012, taking an overdose of Tylenol. Roy's mother testified at Carter's trial that Roy seemed to improve after he began taking medication and getting counseling. He graduated from high school in 2014 and had plans to attend college, she said.

Carter, then 17, also had struggled with depression, as well as anorexia, and had been prescribed antidepressants.

Carter's lawyer, Joseph Cataldo, said Roy was intent on killing himself and took Carter along on his "sad journey." Cataldo said Carter was struggling with "baggage" of her own at the time.

A psychiatrist who testified for the defense said Carter was suffering from side effects from an anti-depressant she was taking.

Cataldo said Carter became "overwhelmed" by Roy's suicidal thinking after she initially tried to talk him out of it and urged him to get professional help.

"It was his constant wearing on Michelle Carter for over a year and a half of 'I want to take my own life,'" Cataldo said.

Cataldo said Roy chose to take his own life, reports CBS Boston, and Carter can't be held responsible for it.

"It's sad, it's tragic," Cataldo said. "But it's just not a homicide."

He pointed to a text to Carter in which Roy wrote, "There is nothing anyone can do to make me want to live."       

The case has been closely watched in the legal community and widely shared on social media. In Massachusetts, an involuntary manslaughter charge can be brought when someone causes the death of another person when engaging in reckless or wanton conduct that creates a high degree of likelihood of substantial harm.

Daniel Medwed, a law professor at Northeastern University, said the judge had a difficult task in determining whether Carter's actions rose to the level of manslaughter. There is no Massachusetts law against encouraging someone to kill themselves.

Medwed said the judge could consider Carter "morally blameworthy," but "moral blame doesn't always equal legal accountability."