The U.S. Supreme Court declined last week to hear Carter's appeal.
Wearing a black turtleneck, a light blazer and black trousers - the same outfit she wore the day she was sentenced - Carter walked off prison grounds surrounded by guards and got into a waiting SUV.
She began serving her time in February 2019, and ultimately served 11 months and 12 days.
"You would think that the judge gave her a sentence that was easy enough for her, but to then let her out on good behavior ... it is very hard", the grandfather said.More news: ‘Shut up’ - Yastremska coach hits back in Wozniacki feud
A MA judge determined Carter, who was 17 at the time, caused the death of the 18-year-old Roy when she ordered him in a phone call to get back into his parked truck, which he'd rigged to fill up with deadly carbon monoxide.
Carter now has to serve five years probation. State parole board members said in their decision that they "remain troubled" that Carter not only encouraged Roy to kill himself, but also actively prevented others from intervening.
Carter's coercive texts drew national attention to the case, and provided shocking insight into toxic teenage relationships and depression. She ordered him in a phone call to get back in his carbon monoxide-filled truck and take his own life, she said.
Carter, then 17, had goaded him to kill himself for days, sending texts such as, "Just do it, babe", and "You said you were gonna do it like I don't get why you aren't" and "I thought you really wanted to die but apparently you don't". While the content of her phone calls is not known, texts Carter sent such as "Just do it, babe", and one in which she told Roy to get back inside a auto rigged to fill monoxide gas, were key to her conviction.More news: AB turns himself in to police
She also participated in a book club.
Although Carter's defense acknowledged her exchanges with Roy, her attorneys argued that prosecutors had "cherry-picked" only those text messages that served their case against her, ignoring others in which Carter urged Roy toward help for his struggles.
Carter's appeal had claimed that her texts were constitutionally protected free speech, and that words alone were not enough to hold someone responsible for another person's suicide.
The lawyers also argued there simply was not enough evidence to prove Carter urged Roy to get back in his truck to die, or that he would have lived if she had called for help or tried to save his life since the phone call was never recorded.More news: Coronavirus epidemic: Death toll rises to 9; details inside
Carter and Roy both lived in MA but met in Florida in 2012 while both were on vacation with their families. Both teens had depression, and Roy had made suicide attempts.