Two bystanders were also hit and wounded as the gunman, who was wearing a mask, finished off the victim, witnesses said.
Chif Insp. Leo Ajero, Kidapawan police chief said Zacaria Batingkay, 38, who lives nearby, was killed instantly. Batingkay was a suspect in a drug case filed at a local court but was granted temporary liberty when he posted bail last month.
The two bystanders were identified as Yazmin Ismael, 27, and Thong Dumacon, 31, all residents of Kidapawan City.
Ajero said they believed personal grudge or family feud was the motive of the killing.
Hour after Batingkay was gunned down, police arrested Bai Nor Sali Ali, 27, a resident of Sultan Kudarat town, Maguindanao in a buy-bust operation.
Police here have stepped up its campaign against illegal drugs and carnapping.