John Ellsworth Hasselbrink, 41, died in the early hours of April 15, 2018, in Ewa Beach, Hawaiʻi, after being shot through the front door of a townhouse he had approached while trying to get inside. Hasselbrink was a Navy chief petty officer in the Pearl Harbor submarine community. Neighbors say he worked a doorknob and pressed against the door as if trying to enter his own home; the resident, Army veteran Gregory A. Farr, was awakened by noise and his barking dog, armed himself, and fired one shot through the closed door. Hasselbrink collapsed on the porch and was pronounced dead at the scene.

Authorities initially treated the shooting as a criminal investigation. Farr was arrested and later released without charges while detectives continued gathering evidence. Prosecutors subsequently charged him with felony manslaughter and two counts of possession of unregistered firearms. A judge dismissed the manslaughter case on speedy-trial grounds in 2019 but left open the possibility of refiling. The case returned to trial, and by July 2022 jurors were deliberating before a judge declared a mistrial when they could not reach a unanimous verdict.

Anyone who knew Hasselbrink, Farr, or who was in the neighborhood that night and has information is asked to come forward.