WOBURN (CBS/AP) – A man sentenced to life in prison for killing a mother and her two young children in Townsend 30 years ago will have to wait 15 more years before he’s eligible for parole, a judge ruled Thursday.

Daniel LaPlante was 17 years old in 1987 when he raped and shot 33-year-old Priscilla Gustafson and then drowned 7-year-old Abigail and 5-year-old William in their home.

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William, Abigail, and Priscilla Gustafson. (Family photo)

LaPlante, now 46, was hoping for a sentence reduction based on court decisions that say juveniles cannot be sentenced to life in prison without parole.  As a result, he asked to be re-sentenced.

LaPlante was hoping to serve the life sentences concurrently, which would make him eligible for a parole hearing after 30 years in prison, which would be later this year.

The prosecution wanted three consecutive life sentences.  That would mean he wouldn’t be eligible for about 15 more years.

Daniel LaPlante in Middlesex Superior Court, March 23, 2017. (WBZ-TV)

LaPlante’s lawyer claimed LaPlante was abused as a child and is now a model prisoner.

But Gustafson’s family and the prosecutor who tried LaPlante say he should never be set free.

“It’s reliving the murders all over again. It’s life-changing again,” said Priscilla Gustafson’s sister Christine Morgan.

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Middlesex Superior Court Judge Hélène Kazanjian. (WBZ-TV)

Middlesex Superior Court Judge Hélène Kazanjian agreed with the family, saying at a hearing Thursday that “Mr. LaPlante has not been rehabilitated.”

She then formally re-sentenced LaPlante to the maximum possible punishment –  three consecutive life sentences, with the opportunity for parole after 45 years from the date of his conviction.

“This case does not involve a single act that resulted in three deaths. Mr. LaPlante committed three distinct and brutal murders. He killed a 33-year-old pregnant mother and her 5-and 7-year-old children. He left a family and community devastated. The court finds that the maximum penalty is warranted,” Kazanjian said.

“As a family we’re very happy, as happy as we could be with the outcome and the circumstances,” said another sister Elizabeth Morgan Williams.

“Is it justice? How can you say it’s justice? He executed Priscillla and her children. When he lifts that life sentence off them, we can lift the life sentence off him,” Priscilla’s brother, Rev. William Morgan Jr., told reporters outside court.

WBZ NewsRadio 1030’s Carl Stevens reports

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(© Copyright 2017 CBS Broadcasting Inc. All Rights Reserved. The Associated Press contributed to this report.)