A 49-year-old farmer was shot dead Saturday night after a daylong drinking session with a younger companion turned violent in Barangay Caruray, San Vicente, Palawan, police said.

The victim, identified only as “Mon,” had been drinking with the suspect, “Nonoy,” 28, and several others from around 10 a.m. to 6 p.m. on 25 April. Investigators said an argument broke out between the two at about 11 a.m., though it was not immediately clear what sparked the dispute.

Hours later, the victim went home to rest and reportedly fell asleep on the stairs. At around 8 p.m., a gunshot rang out. His live-in partner, who was at a nearby house at the time, rushed over and found him lying bloodied.

He was taken to a hospital but was declared dead at 1:17 a.m. the next day.

Police who responded to the scene recovered two improvised shotguns, now being examined as part of the investigation.

In a statement, the Palawan Police Provincial Office said it is building a case against the suspect and is working to establish the full circumstances behind the killing.

“We are exhausting all efforts to ensure the immediate filing of appropriate charges,” said Provincial Director Police Colonel Joel D. Casupanan.

Authorities arrested the suspect at around 6:40 a.m. on April 26 in a hot pursuit operation.

Police have yet to disclose the motive, but investigators are looking into the earlier altercation during the drinking session as a possible trigger.