Lawyer Eufronio Hernandez, the NBIs Central Mindanao director, said the family of councilor Alexis Costales, who was gunned down last month, gave no reason for asking the Task Force Costales to end its probe.
"They made clear that they would leave everything to God. All they asked was for us to put an end to our efforts in solving the crime," he said.
Hernandez earlier admitted that the killing of Costales, a popular member of the city council, could be the "toughest case" he had ever handled in his 40 years in the NBI.
Hernandez said there were no witnesses who could help them identify the killers of Costales. The councilors six-year-old nephew, Clarence Cang, was also slain in the attack.
Police also had no solid clues on the case, except for suspicions that hired killers could have pulled off the killing.
Costales and his nephew were on their way home from church when two motorcycle-riding men flagged them down and shot them with handguns.
Since January, there have been 19 other unsolved killings here. John Unson