NORTHAMPTON, Mass. – Three Massachusetts teenagers pleaded not guilty through their lawyers Tuesday in the bullying of a 15-year-old girl who committed suicide after what prosecutors call months of threats and harassment.

The teens were not required to appear at the hearing in Hampshire Superior Court.

Sean Mulveyhill and Kayla Narey, both 17 and from South Hadley, and 18-year-old Austin Renaud, of Springfield, will remain free on personal recognizance on the condition that they stay away from the family of Phoebe Prince, the girl who died.

Mulveyhill and Renaud are charged with statutory rape. Mulveyhill and Narey are also charged with violation of civil rights resulting in bodily injury, criminal harassment and disturbance of a school assembly.

They are among six teens charged in what prosecutors said was the “unrelenting” bullying of Prince, who hanged herself Jan. 14. Prince, who had emigrated from Ireland last summer, was a freshman at South Hadley High School.

Authorities said she was harassed and bullied after having a brief relationship with a popular boy. They have not identified the boy, but friends said it was Mulveyhill, who was a star football player at South Hadley High.

Prosecutors said the bullying went on for three months, and included insults and threats made in school and through cell phone text messages. Prince killed herself after a day of near-constant bullying, including being hit with a beverage container as she walked home from school.

Renaud’s lawyer, Terrence Dunphy, would not comment on the relationship between Prince and Renaud or the statutory rape charge against him. Dunphy said lawyers have not received information from prosecutors on what evidence they have.

“I can’t get into the defense when I don’t know what the evidence is,” Dunphy said after the hearing.

A pretrial hearing for Mulveyhill, Narey and Renaud was scheduled for Sept. 15.

The three other teens in the case — Ashley Longe, Flannery Mullins and Sharon Chanon Velazquez, all age 16 — are scheduled to be arraigned Thursday in Franklin-Hampshire Juvenile Court in Hadley. They are charged with violation of civil rights with bodily injury.

The three also face charges of juvenile delinquency.

Several news outlets, including The Associated Press, have been reporting since charges were announced last week that nine youths had been accused in the case. Because prosecutors by law cannot release the names of those charged as juvenile delinquents, they did not clarify that the three 16-year-olds were charged twice — once as delinquents and once as youthful offenders.

A person familiar with the proceedings confirmed to the AP on Tuesday on the condition of anonymity that six teens were involved.