TAUNTON — A lawyer for a Plainville teen charged with manslaughter after being accused of encouraging her friend to kill himself asked a judge Tuesday to put the case on hold until the state’s highest court decides her appeal.

Joseph Cataldo, a lawyer for Michelle Carter, argued Tuesday that the criminal case against her should not move forward until the Supreme Judicial Court decides on an appeal of a judge’s refusal to dismiss the manslaughter charge.

Prosecutors argued the case should move forward while the appeal is pending.

Another judge heard the arguments Tuesday but did not immediately rule.

Carter, then 17, is accused of sending 18-year-old Conrad Roy III dozens of text messages encouraging him to take his own life. Roy’s body was found in his pickup truck in Fairhaven on July 13, 2014. He died of carbon monoxide poisoning.

In September, a judge rejected a defense motion to dismiss the charge, citing records that prosecutors have said show Carter was on the phone with Roy for about 45 minutes while he was inhaling carbon monoxide, heard him moaning, and did not call 911. The judge also cited text messages Carter sent to a friend, saying she told Roy to get back in his truck when he became afraid.

Cataldo argues that Roy, from Mattapoisett, made his own decision to commit suicide and that Carter tried to talk him out of it. The court is expected to hear the appeal in May.