The Supreme Court on Monday declined to hear the case of a Massachusetts woman who sent her boyfriend text messages urging him to kill himself. Michelle Carter is serving a 15-month sentence after being convicted of involuntary manslaughter in the 2014 death of her boyfriend, Conrad Roy III, but she's expected to be released this month.

A judge determined that 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 in his carbon monoxide-filled truck that he'd parked in a Kmart parking lot. The phone call wasn't recorded, but the judge relied on a text Carter sent her friend in which she said she'd told Roy to get back in.

In text messages sent in the days leading up to Roy's death, Carter also encouraged Roy to follow through with his suicide plan. She chastised him when he didn't, Massachusetts courts found.

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Carter was convicted of involuntary manslaughter in June 2017, but a judge ruled she could remain free on bail as her lawyers appealed the case. The Massachusetts Supreme Judicial Court upheld the conviction in February 2019, and a judge then ordered her to begin serving her sentence. Her lawyers asked the U.S. Supreme Court to take up the case in July, calling the conviction an "unprecedented" violation of her free speech rights that raised crucial questions about whether "words alone" are enough to hold someone responsible for another person's suicide.

Jail officials said Carter has accrued enough "good time" credits for good behavior and attending programs while incarcerated after she was denied parole last September. Jail officials confirmed to CBS Boston her anticipated released date is now January 23.

Joseph Cataldo, one of Carter's lawyers, called Monday's decision an "injustice" and said that the legal team is weighing its next steps. He didn't elaborate.

Carter's case has garnered national attention and sparked legislative proposals in Massachusetts to criminalize suicide coercion. In a similar case last October, a former Boston College student was indicted on an involuntary manslaughter charge for allegedly encouraging her boyfriend to take his own life with text messages. "48 Hours" covered the case in the episode "Death by Text."