Carter, 20, cried silently in the Massachusetts courtroom as Judge Lawrence Moniz outlined the steps she took -- and the ones she did not take -- that led to Roy's death from carbon monoxide poisoning.
"She called no one, and finally, she did not issue simple additional instruction: Get out of the truck," Moniz said in his 15-minute explanation.
Carter is expected to be sentenced August 3, when she could face up to 20 years in prison for the manslaughter charge.
But Northeastern University law professor Daniel Medwed said he does not expect Moniz to condemn her to two decades behind bars.
"I think the judge might show her leniency, given her mental health issues and medications
," as a psychiatrist testified about in her trial, Medwed said. "The conviction sends a strong message, but that doesn't mean the outcome will be 20 years in prison."
Where could she serve her time?
Carter was 17 when Roy died, and she was charged as a juvenile.
Since she is now a legal adult, Medwed said Carter could likely serve any jail time in an adult prison.
Kari Hong, an assistant professor of law at Boston College, said Carter could serve what's known in the state as a "hybrid" sentence.
That would allow Carter to serve part of her sentence under the juvenile system, which aims to rehabilitate, and part under the adult system, which aims to punish offenders.
Could Carter face a civil suit?
Carter's time in court is not yet done.
The Roy family could sue her for the wrongful death of their son since she was found guilty beyond a reasonable doubt.
Medwed said the only issue would be whether Carter and her family have the assets or the means to fight a civil suit and pay any damages.
Could this case set a legal precedent?
Medwed said the case is not likely to set a legal precedent, "especially since it still needs to survive appeal."
But it could "embolden other prosecutors to be more aggressive in their charges" since it has "such a symbolic value," he said.
The verdict is not likely to hold up in appellate courts, Hong said. She predicted the verdict will be overturned on causation, which would lead to state lawmakers introducing a new law to criminalize the act of encouraging suicide.
"What happens in Massachusetts is there's a functional relationship between the court and the legislature," she said. "When the court shuts down the legislature, the Massachusetts legislature writes a new law."
Could the case lead to new laws?
Massachusetts is one of 10 states without laws that criminalize encouraging or assisting suicide.
But since Carter was miles away from Roy when he died, in his ruling, Moniz focused on the hundreds of text messages and calls the couple exchanged on the night of his death.
The messages from Carter to Roy encouraged the then-18-year-old to commit suicide, saying his family will understand and he needs to stop "pushing it off."
Medwed said the case is likely to set the groundwork for introducing legislation in Massachusetts.
Hong agreed, saying that because the state legislature does not have an adequate law in place to address this kind of case, they are more likely to introduce a law criminalizing this type of behavior in the near future.