Attorneys for Michelle Carter, who was convicted of involuntary manslaughter in her boyfriend's suicide, have filed an appeal with the United States Supreme Court, according to the Cataldo Law Offices in Massachusetts.
Carter, now 22, is serving 15 months in jail after she was sentenced in the July 2014 suicide of Conrad Roy III, who died from carbon monoxide poisoning after locking himself in his truck. Investigators later discovered text messages from Carter, then 17, encouraging Roy to take his own life, WFXT reported.
Massachusetts' highest court upheld her involuntary manslaughter conviction earlier this year.
Carter's lawyers had said they would consider all legal options, including an appeal to the U.S. Supreme Court. They said they continue to believe she is not responsible for Roy's death.
The trial judge found that Carter caused Roy's death when she instructed him to get back inside the truck when he tried to escape the fumes, WFXT reported.
– The Associated Press contributed to this report.