A 20-year-old American woman was convicted of involuntary manslaughter Friday for pushing her teenage boyfriend to kill himself, in a decision likely to break new legal ground.
Michelle Carter broke down in tears and sobbed into a tissue when Judge Lawrence Moniz read out the verdict at a brief hearing in the court in Taunton, south of Boston in Massachusetts.
"This court, having reviewed the evidence, now finds you guilty on the indictment charging you with involuntary manslaughter," Mr Moniz told the court.
Michelle Carter cries in court as she's convicted of involuntary manslaughter. (AAP)
Conrad Roy, 18, was found dead in his pickup truck in July 2014. (Supplied)
Carter, who waived her right to a jury trial, faces up to 20 years in prison. She is due to be sentenced on August 3.
Conrad Roy, 18, was found dead from carbon monoxide poisoning in his pickup truck in a parking lot in July 2014.
The trial heard that Carter and Roy exchanged hundreds of text messages in which Carter urged him to follow through on his plan to kill himself, urged him to conceal it from his parents, lie to his mother and select a secluded parking lot.
In several texts revealed in court, the then 17-year-old told him: "You can't think about it. You just have to do it. You said you were gonna do it."
While legal experts say Carter may have encouraged him to take his own life, they had questioned whether it is enough to secure a conviction under involuntary manslaughter.
Prosecutors noted Carter admitted responsibility in a text message to a friend almost two months after Mr Roy's death.
The northeastern state of Massachusetts, unlike other US states, has no law against encouraging someone to commit suicide.
The defence argued that Mr Roy had been on a path to suicide "for years" and sought to minimise Carter's role in her boyfriend's life, saying the pair were in a "long-term texting relationship" and had met in person only a handful of times.
Carter's case was tried in a juvenile court because she was a minor at the time.
If you are experiencing mental health issues or suicidal feelings contact Lifeline on 13 11 14 or Beyond Blue 1300 224 636. In an emergency call 000.