More than 20 years after Paul Herlihy was beaten to death, court records detail how investigators say they built a case against his son.
According to an arrest affidavit shared with ABC News, investigators interviewed friends and relatives of Paul and Douglas Herlihy about the events and family tensions that preceded the 50-year-old man’s 2003 killing.
About a month before Douglas Herlihy’s arrest, investigators arranged a phone conversation between him and his brother. Court records say statements made during that call did not match his earlier account.
Christopher Knowles, chief of the New Hampshire Attorney General’s Cold Case Unit, described Douglas Herlihy’s account in court, according to WMUR. The fatal confrontation followed a physical struggle between father and son, the ABC affiliate reported.
Knowles said Douglas Herlihy told investigators he took a baseball bat kept behind the family’s front door and struck his father, causing his death, according to WMUR.
A friend also told investigators that Douglas Herlihy had complained during the summer of 2003 that his father frequently hit him, according to the affidavit.
Douglas Herlihy, now 40, pleaded guilty Wednesday to manslaughter and attempted falsification of physical evidence in connection with his father’s death, New Hampshire Attorney General John Formella said.
The pleas were entered under a proposed agreement that still requires the court’s approval, the attorney general’s office said.
Under the agreement, Herlihy would receive a 12- to 24-year sentence in New Hampshire State Prison for manslaughter, according to Formella.
He would also receive a three-and-a-half- to seven-year sentence for attempted falsification of physical evidence. That sentence would be suspended for 20 years, the attorney general said.
The remaining charges, including second-degree murder, would be dismissed under the agreement, according to the attorney general’s office.
“The New Hampshire Cold Case Unit and our law enforcement partners remain committed to pursuing answers and accountability, even decades after a crime,” Formella said in a statement. He praised the investigators and prosecutors whose persistence led to what he called an important resolution.
Formella said the case serves as a reminder that “the pursuit of justice does not end with the passage of time.”
A sentencing hearing is expected to be scheduled for early 2027, the attorney general’s office said.
Months leading up to Paul Herlihy’s death
Court documents state that Paul and Douglas Herlihy were the only occupants of a Milford residence Paul purchased in December 2002 when the killing occurred.
The arrest affidavit described Douglas Herlihy’s relationship with several relatives as “tumultuous,” citing physical confrontations and violence between him and his father.
In the months before his death, Paul Herlihy contacted police at least eight times because of his son’s behavior. On some occasions, he sought to have Douglas removed from the home, the affidavit said.
YOU MAY ALSO READ: Cornell Rape Accuser May Remain Jane Doe; Judge Warns Federal Charges
Paul Herlihy also enrolled his son in a school for students with behavioral disorders. According to the affidavit, Douglas attempted to avoid attending the school.
On Aug. 12, 2003, police found Douglas Herlihy inside his father’s vehicle, which had been reported stolen. Officers discovered drugs and other illegal items in the car, and the affidavit said he was charged with several offenses.
Douglas Herlihy was arraigned and released after his father posted bail, according to the affidavit.
On Aug. 18, 2003, Paul Herlihy brought his son to the Milford Police Department to self-surrender for the stealing of the car, the affidavit said. Doug Herlihy pled guilty to that charge in Milford District Court andthe
Paul Herlihy was killed in his Milford residence between Aug. 23, 2003, and Aug. 27, 2003, the attorney general's office noted.
He was found in his home on Aug. 27, 2003, during a welfare check carried out by Milford Police, according to the affidavit.
Responding officers found hundreds of flies and a strong odor of decomposition in the residence when they arrived, according to the affidavit. In the kitchen, it says they found a rug that was pulled up and rolled and a blue tarp covering the carpet. When they removed the tarp, they discovered what was later determined to be the body of Paul Herlihy within the carpet, according to the affidavit.
An autopsy determined the death was a homicide as a result of blunt force trauma, the affidavit said. It noted that the chief medical examiner found that Paul Herlihy also had a broken nose, a jaw fracture and basal skull fractures.
The arrest
Investigators orchestrated a phone call between Douglas Herlihy and his brother Andrew Herlihy in May 2025 in which Douglas Herlihy claimed he sat down for interviews with investigators and said they determined it would have been impossible for him to have anything to do with his father's death, according to the affidavit.
But, investigators said that there is no evidence Douglas Herlihy participated in an interview with the cold case investigators looking into his father's death, the affidavit said.
Douglas Herlihy also told his brother that police broke down the time of death to within an hour or two and, based on cameras on Route One, determined it would have been impossible for him to have anything to do with his father's death, according to the affidavit.
Investigators say they found nothing to indicate police either located or were directed toward any surveillance video that would exclude Douglas Herlihy as a suspect in his father's death, according to the affidavit.
Douglas Herlihy was arrested and charged in the death of his father in June 2025, according to the attorney general's office, which said he was initially charged with second-degree murder in his father's death.
