Sibulan: Three suspects charged in the fatal shooting of American marine biologist Dr. Kent Carpenter in Sibulan, Negros Oriental have tested positive for illegal drug use, a police official said Tuesday.

According to Philippines News Agency, Capt. Stephen Jaynard Polinar, spokesperson of the Negros Oriental Police Provincial Office, identified the suspects only by their aliases M.O., J.F., and C.D. "The first two suspects were arrested after the crime was committed, while the third voluntarily surrendered to authorities later," Polinar stated during a virtual press briefing.

The drug test results are expected to be part of the evidence in the robbery with homicide case already filed against the suspects. Polinar did not confirm if separate charges for illegal drug use would be pursued. He also revealed that a sixth person of interest has been identified, following information provided by the other suspects.

The case has been forwarded to the court by the Provincial Prosecutor's Office, leading police to withhold further details to avoid impacting the proceedings. Polinar clarified that Carpenter's Filipino live-in partner's brother is not among the suspects.

Police investigation and security camera footage showed five suspects at Carpenter's residence in Barangay Ajong, Sibulan during the July 12 attack. Three allegedly entered the house, while two acted as lookouts. However, one suspect later claimed that a sixth individual was involved, though his role is yet to be determined.

Meanwhile, the remains of the 73-year-old scientist have been cremated and will be taken to the Silliman University Church for a necrological service. Carpenter was an adjunct professor at the Silliman University Institute of Environmental and Marine Sciences and a research affiliate at the Angelo King Center for Research and Environmental Management. He was renowned for his research on Philippine marine biodiversity, particularly identifying the central Philippines as a key area for marine shore fish diversity.