Shedevil: This lady coerced her boyfriend to kill himself.

CNN is reporting that almost three years ago, Massachusetts teenager Conrad Roy III was found dead from carbon monoxide poisoning in his pickup truck in a Kmart parking lot.

His girlfriend posted grieving messages on social media and raised money in his name for mental health awareness. His friends and family lamented a young life cut short by suicide.

But before long prosecutors came up with another, more sinister, theory about what happened. And within months they indicted the girlfriend, saying they had discovered numerous text messages from her urging Roy to kill himself.

Michelle Carter, who was 17 at the time, goes on trial this week in a Taunton, Massachusetts, courtroom on involuntary manslaughter charges. She waived her right to a jury trial Monday, meaning her case will be decided by a judge who will hear testimony and render a verdict.

Carter, now 20, is being tried as a youthful offender because she was a minor when her alleged crime took place.

Roy, 18, was found dead in his truck on July 13, 2014, in Fairhaven, Massachusetts. Police say he used a combustion engine to fill the cabin with carbon monoxide.

The day before, authorities say, Carter had urged him to go through with his plan to commit suicide.

"You need to do it, Conrad," Carter told Roy in a text message the morning of July 12, according to a document disseminated by the Bristol County District Attorney's Office.

"You're ready and prepared. All you have to do is turn the generator on and you will be free and happy," she reportedly wrote. "No more pushing it off. No more waiting."

According to the District Attorney's office, Roy drove that day to the Kmart parking lot, nearly 40 miles from his home. At one point, he got out of his truck and spoke to Carter for more than 40 minutes on the phone, telling her that he was having second thoughts about taking his life, prosecutors said.  But she told him to get back into the car, according to the document.

CNN