Neighbors say Kauai police failed to stop gunman before homicide

Neighbors in Kīlauea say Kaua‘i police were warned for months that William “Billy” Sinclair was waving guns, making threats and firing weapons on his property, yet Sergio Reyes Hernandez was still found dead in Hanalei before officers arrested Sinclair. The case has left residents questioning why repeated alarms, restraining orders and reports of gunfire never produced stronger intervention.

Court documents say Hernandez, 37, was found dead at 12:47 a.m. June 6 in a restaurant bathroom in Hanalei with three puncture wounds consistent with bullet holes. A bullet projectile resembling a 9mm round was recovered from the bathroom floor. Hernandez’s girlfriend told police he had been in a dispute with Sinclair over $10,000 to $12,000 in compensation for property damages.

The timeline widened police scrutiny. Gunfire was reported near Sinclair’s residence in Kīlauea about 4:39 a.m. June 6, and a separate person told police Sinclair had shot at him near the home and was “known to pull guns on people.” Sinclair was arrested June 8 after a dayslong manhunt that ended in Kapa‘a, about 15 miles from Kīlauea. Police later recovered a loaded Glock 9mm pistol and a grocery card belonging to Hernandez from the ocean after Sinclair jumped in during the pursuit.

Residents say the danger was not new. In the year before Sinclair’s arrest, they repeatedly called police to report that he was brandishing firearms, making threats and shooting on his property. Neighbors also obtained restraining orders that barred him from possessing firearms or ammunition. After Sinclair’s arrest, police found what investigators described as an arsenal: three pistols, two shotguns, two semi-automatic handguns, 13 rifles, three suppressors and ammunition.

Kaua‘i Police Department public information officer Tiana Victorino said the department cannot comment on specifics while the investigation is ongoing. She said that when a temporary restraining order is served, officers review firearm registration records and may recover registered firearms, take custody of guns in plain sight or found in a consensual search, or accept firearms surrendered by the respondent. If officers cannot locate firearms named in a TRO petition, she said, they can ask the court for a search warrant.

Sinclair was indicted on 28 counts, including second-degree murder, second-degree attempted murder and multiple firearm offenses. He pleaded not guilty June 18. Judge Michael Soong said the state may seek an extended term of imprisonment, which could mean life without the possibility of parole if Sinclair is convicted. Bail was raised from $500,000 to $1.5 million, with a bail hearing set for June 25 and trial scheduled for Sept. 28. For many on Kaua‘i, the unanswered question is no longer what Sinclair had, but why repeated warnings did not stop him sooner.