including for drugs and a stolen vehicle. When speaking with police after an arrest in 2020, he told an officer that he knew the court would  throw out the charges. 

 That's what I do. I beat cases. I beat my first body when I was 17!  he said, according to his arrest affidavit.

 I assumed he was implying that he had killed people in the past,  the officer said.

FOLLOW THE FOX TRUE CRIME TEAM ON X

But Douglas Herlihy consistently denied any involvement in the killing of his father to family, court records show.

When investigators approached him in 2010 about the investigation into his father's killing, Douglas Herlihy referred them to his attorney.

Based on the investigation's findings, an arrest warrant for Douglas Herlihy was issued in June 2025. He was quickly arrested in Saugus, Massachusetts, and was later extradited to New Hampshire.

SIGN UP TO GET THE LATEST TRUE CRIME NEWS

Douglas Herlihy was charged with two counts of second-degree murder and falsifying physical evidence.

CLICK HERE FOR MORE FROM THE FOX TRUE CRIME HUB

He negotiated a plea agreement for 12 to 24 years in the New Hampshire State Prison on a manslaughter charge. The agreement also suspends for 20 years a potential sentence of 3 ½ to 7 years for attempting to falsify evidence.

SEND US A TIP

 This case is a reminder that the pursuit of justice does not end with the passage of time,  said New Hampshire Attorney General John M. Formella.

GOT A TIP?

 The New Hampshire Cold Case Unit and our law enforcement partners remain committed to pursuing answers and accountability, even decades after a crime. That work takes persistence, patience and a determination to follow the evidence wherever it leads. I commend the investigators and prosecutors whose continued efforts brought this case to an important resolution. 

LISTEN TO THE NEW 'CRIME   JUSTICE WITH DONNA ROTUNNO' PODCAST

A sentencing hearing will be scheduled for a date in early 2027.

GET BREAKING NEWS BY EMAIL

The Herlihy family said they wanted to maintain their privacy and did not wish to speak with the media according to the New Hampshire Department of Justice Cold Case Unit.

CLICK HERE TO DOWNLOAD THE FOX NEWS APP

Herlihy's attorney could not immediately be reached for comment.

Find more on this story at foxnews.com.