Police investigators tracking the fatal shooting of an American marine biologist in Negros Oriental are searching for two brothers implicated in the attack, though officials now consider the case solved but not closed.

During a press briefing at Camp Crame, Philippine National Police (PNP) spokesperson and information chief Col. Allen Rae Co said investigators identified the brother of a fugitive known only as “Eden” as a participant in the killing of Dr. Kent Carpenter.

To recall, Carpenter was killed at his home in Barangay Ajong, Sibulan, on 12 July.

Co said the four suspects already in custody have undergone inquest proceedings. Formal charges against the two remaining fugitives will be submitted to the prosecutor’s office through regular filing.

“We now have six suspects in the Carpenter case,” Co said. “The first two were caught, two surrendered, and it appears alias Eden and his brother were also involved. We filed inquest cases for the four, and for the two who are still at large, it will be a regular filing with the prosecutor.”

Under PNP guidelines, a case is classified as “cleared” once suspects are identified and charged, and “solved” when at least one suspect is arrested. “In this case, since we have four in custody, it is considered solved,” Co added.

Despite the identification of new suspects, the PNP maintained that robbery remains the primary motive behind the slaying.

“We have not seen anything to indicate otherwise,” Co said, downplaying speculation that the crime was related to Carpenter’s professional work.

“Although we are looking at everything, this is not over. It doesn’t mean that because we have identified the suspects and fil