A Vermont man who was 17 when he and a friend killed a pair of married Dartmouth College professors 25 years ago is now seeking a significantly reduced prison sentence as his high-profile resentencing hearing begins this week in New Hampshire.
Robert Tulloch, now 43, pleaded guilty to first-degree murder in the 2001 stabbing deaths of Half and Susanne Zantop at their home in Etna, New Hampshire. Under state law at the time, he automatically received a sentence of life without the possibility of parole. But a landmark 2012 U.S. Supreme Court decision determined that mandatory life sentences without parole are unconstitutional when imposed on juveniles, and that ruling has since been applied retroactively to hundreds of cases nationwide.
The resentencing hearing, which marks the final such proceeding for five men serving mandatory life sentences in New Hampshire for crimes committed as teenagers, is scheduled to run through Wednesday at Grafton County Superior Court in North Haverhill. Tulloch’s defense team is arguing that a minimum sentence of 30 to 40 years would be appropriate based on comparisons to similar cases that have been resentenced following the Supreme Court ruling.
The crimes themselves were senseless and calculated. According to prosecutors and court records, Tulloch and his then-16-year-old accomplice James Parker spent months planning to rob and kill strangers to finance a trip to Australia. They knocked on doors in New Hampshire and Vermont under the pretense of conducting environmental surveys, seeking wealthy homeowners to target.
On January 27, 2001, they gained entry to the Zantop home by using that same survey ruse. Half Zantop, 62, was a professor of Earth sciences at Dartmouth who had been teaching there since the 1970s. His wife, Susanne Zantop, 55, was chair of the college’s German studies department and held a PhD from Harvard University. The couple had emigrated from Germany and had been living in the United States for decades.
According to Parker’s account to prosecutors, Tulloch stabbed Half Zantop, then directed Parker to attack Susanne Zantop. Tulloch also stabbed her fatally. The two teens fled with $340 from Half’s wallet, leaving behind evidence including fingerprints on a knife sheath and a bloody boot print. They hitchhiked west and were arrested weeks later at an Indiana truck stop.
Parker, who cooperated with prosecutors in exchange for a reduced charge, pleaded guilty to being an accomplice to second-degree murder and was sentenced to 25 years to life. He was released on parole in 2024 after serving nearly the minimum term of his sentence. As part of his release conditions, he has been forbidden from any contact with the Zantop family and remains under supervision for the rest of his life.
Tulloch, by contrast, has remained in prison since his conviction. His defense attorneys, Richard Guerriero and Oliver Bloom, argue that he has demonstrated significant rehabilitation and maturation over more than two decades in custody. They point to prison records showing no major infractions since 2012 and no minor infractions since 2017. They note that the vast majority of his disciplinary write-ups have been for possessing too many books. In therapy sessions conducted in prison, they say, Tulloch has consistently expressed remorse for what he describes as a heinous and unforgivable crime, and has demonstrated what they characterize as a strong capacity for empathy.
Tulloch’s case has taken years to reach this point. In 2018, he first argued that sentencing him to life without parole violated the New Hampshire Constitution. A state judge referred that question to the New Hampshire Supreme Court, but it declined to rule. However, in July of last year, Superior Court Judge Lawrence MacLeod found that a state law requiring lifetime sentences without parole for capital crimes violated the state constitution’s prohibition against cruel and unusual punishment when applied to juveniles.
The state has not yet publicly indicated what sentence it will seek, though a judge ruled earlier this year that prosecutors cannot argue for Tulloch to receive the same life-without-parole sentences he currently holds.
Nationally, the outlook for other juvenile lifers who have been resentenced following the 2012 Supreme Court ruling offers some context for what Tulloch might expect. According to a study published in 2024 in the Journal of Criminal Justice, more than 75 percent of juvenile lifers nationwide who have been resentenced have received sentences of less than 40 years. In New Hampshire, the four other inmates resentenced before Tulloch received sentences ranging from 25 to 45 years, with one exception: a man who refused to attend his hearing was resentenced to life without parole.
The case has larger implications for New Hampshire’s approach to juvenile sentencing. State lawmakers have repeatedly rejected efforts to ban life sentences for juveniles, making Tulloch’s case a potential catalyst for legislative change. New Hampshire remains one of only 22 states that has not banned life sentences without parole for juveniles, though 28 states and the District of Columbia have enacted such bans. Five additional states allow the sentence in theory but have no one currently serving it.
Human rights organizations and criminal justice advocates have filed briefs in support of Tulloch’s resentencing, arguing that developments in neuroscience and the legal system’s evolving understanding of juvenile culpability and rehabilitation potential support a sentence with the possibility of eventual parole. The American Civil Liberties Union of New Hampshire has emphasized that despite decades of consensus that children are less culpable than adults and more capable of change, New Hampshire continues to permit irreversible punishments for juveniles certified as adults.
The resentencing hearing represents one of the most significant criminal justice moments in New Hampshire in recent years, touching on fundamental questions about punishment, redemption, and the constitutional rights of those who commit serious crimes while still children.