The last time the family of Priscilla Gustafson saw the man who killed her and her two young children, he had just been sentenced to three consecutive life terms — the maximum punishment allowed but one that the judge described as too lenient.
Nearly 29 years later, Gustafson’s relatives are expected to face Daniel J. LaPlante again Wednesday in Middlesex Superior Court.
That is when a judge will consider LaPlante’s request to have his punishment reduced, a petition that arose from court cases that banned life-without-parole sentences for those convicted of murders as juveniles.
“He is so vile,’’ Gustafson’s sister, Elizabeth Williams, said Wednesday in a telephone interview. “My sister and her babies — they’re murdered. They’re gone. And he has all these privileges.’’
LaPlante was 17 years old on Dec. 1, 1987, when he fatally shot a pregnant Gustafson, 33, with a stolen gun and drowned her 7-year-old daughter, Abigail, and son, William, 5, in separate bathtubs in their Townsend home, court records show. Investigators also found evidence that LaPlante, who lived nearby, had raped Gustafson.
Now 46 and imprisoned at the Massachusetts Treatment Center in Bridgewater, LaPlante is no longer bound to spend the rest of his life in prison under a 2013 Supreme Judicial Court decision that struck down life sentences without parole for juveniles.
Many inmates affected by the decision are eligible for parole after 15 years, but not LaPlante. His attorney, Ryan M. Schiff, noted in court papers in 2015 that because LaPlante had been sentenced to three consecutive life terms, he would have to spend 45 years in prison before asking for freedom.
Later that year, the SJC ruled that prisoners such as LaPlante could ask a judge to consider imposing concurrent life terms — a move that could potentially make him eligible for parole this year.
Former state attorney general Thomas F. Reilly, who prosecuted LaPlante, said he should never be set free.
“He will kill again if ever released from prison,’’ said Reilly, who described the crime scene as “the most terrible’’ he has ever seen. “He’s evil.’’
Prosecutors said they want LaPlante’s sentence to remain the same. Though courts have recently concluded that research shows the juvenile brain isn’t fully developed, the Middlesex district attorney’s office said LaPlante planned the slayings.
“While the Commonwealth appreciates the role youth may play for persons who committed murders before they turned 18, we maintain that the evidence overwhelmingly demonstrates that LaPlante’s chronological age played no role in the murders,’’ said Meghan Kelly, a spokeswoman for Middlesex District Attorney Marian T. Ryan.
Retired Superior Court Judge Robert Barton, who sentenced LaPlante, called the case the most vicious during his 22 years on the bench.
“If I had the death penalty in those days, I would have sentenced him to the death penalty,’’ Barton said Wednesday. “It was a savage killing.’’
Weeks before the murders, LaPlante broke into several neighborhood homes, stealing guns and cash from one house and taking a cordless telephone, coins, and television equipment from the residence where Gustafson lived, court papers show.
At the time, LaPlante was free on $10,000 bail on charges that he had broken into his ex-girlfriend’s home and threatened her and others with a hatchet, according to an October 1988 Globe report.
The day of the killings, Gustafson, who ran a nursery school, and her son came home to find LaPlante inside, said Williams, Gustafson’s sister. Abigail was killed after returning home from school. Investigators found a copy of “Little Women,’’ the book she was reading, in her bedroom.
Gustafson’s husband, Andrew, discovered the crime after he returned home from finishing a real estate deal, Williams said. A longtime lawyer, Andrew Gustafson died of esophageal cancer in 2014 at age 60, his sister-in-law said.
Two days after the killings, LaPlante broke into two homes in Pepperell, stealing a revolver, and he tried to get into a third residence, prosecutors said. At one home, he held up a woman at gunpoint and ordered her to drive him to Fitchburg. The woman escaped, but LaPlante kept driving and was later arrested in a trash bin in Ayer, court records show.
During questioning, police found LaPlante had hidden a revolver in his underwear and concealed a bullet inside his right sneaker, prosecutors said. A jury convicted him of the three murders in 1988.
At LaPlante’s sentencing, no consideration was given to his age and evidence about his upbringing wasn’t introduced, Schiff, the defense attorney, wrote in court papers.
Schiff said as a child, LaPlante was subjected to “extreme psychological abuse’’ by his father, sexually abused by a psychiatrist, and struggled with dyslexia and hyperactivity disorder.
Since his imprisonment, LaPlante has assumed leadership roles in prison groups and completed college-level courses, Schiff wrote. He and LaPlante’s mother didn’t respond Wednesday to requests for comment.
LaPlante has turned to the courts before to improve his life in prison. In 2001, he successfully sued prison officials, asserting he was deprived unfettered access to the prison law library and was mislabeled as a sex offender. After the state lost, a federal judge ordered that LaPlante’s attorneys be paid nearly $100,000 in legal fees.
Gustafson’s other sister, Christine Morgan Bryant, said LaPlante’s request for a reduced sentence has been devastating.
“I don’t think he has been rehabilitated. He never showed any desire to be until there was a possibility of parole,’’ Morgan Bryant said. “It just doesn’t make any sense at all.’’
Laura Crimaldi can be reached at laura.crimaldi@globe.com.
