The Criminal Investigation Detection Team headed by Superintendent Nolasco Bathan said 10 men wearing black shirts seized businessman Mario Pastrana, 49, from his house in Barangay Bulusucan.
Bathan said Pastranas son, Arnold, 26, resisted and was shot twice in the chest.
The armed men fled with the elder Pastrana, carting away his M-16 rifle and two short firearms.
Police said they were still trying to establish the motive for the killing and abduction.
Early last month, 10 unidentified men gunned down Ricardo Valmocina Sr. and his son, Roel, of nearby Barangay Pinaod, and kidnapped Valmocinas other son, Ricardo Jr. Dino Balabo