Karapatan-Central Visayas said the task force is not credible as it was created by President Gloria Arroyo whom they accused of masterminding the political killings in the country.
It added that an independent and credible probe can only be undertaken by those who have a "steep track record of deep respect for human rights, social justice, peace and democracy."
Karapatan-Central Visayas chairman Alfonso Cinco said that former Supreme Court Justice Jose Melo, the head of group tasked by Arroyo to investigate the killings, was bragging that there would be no "sacred cow" in the course of his probe.
Human rights groups and progressive organizations are blaming Arroyo's all-out-war policy for more than 136 political killings this year alone.
It added that until now, Arroyo and her allies "conveniently find excuse to snob senate inquiries on a host of presidential scandals in spite of the Supreme Court ruling condemning Arroyo's gag order (Executive Order 464) as unconstitutional."
Karapatan also said that Arroyo has already set the tone for the investigation when she hoisted as supreme truth the result of investigation of the PNP Task Force Usig.
"Like the Melo Commission, TFU was earlier formed by Arroyo to ostensibly investigate political killings. In matter of weeks, it eagerly came up with results that please all the butchers in government," Karapatan added.
Meanwhile, another vigilante-style killing happened last Friday night at the corner of Magallanes and Plaridel streets in barangay Ermita.
Police have yet to identify the victim who is estimated 5'4" to 5'5" tall, of medium build, in his 30's and wearing a black t-shirt, short pants and a ball cap.
Witnesses told SPO3 Alex Dacua of the Homicide Section that three unidentified men approached the victim then suddenly shot him several times hitting him in the back and head, killing him instantly.
The assailants then hurriedly left the area, but no one saw if they got on a getaway vehicle.
Police could not yet determine if the shooting is related to the killings attributed to so-called vigilantes who have been blamed for 168 deaths since December 22, 2004.
Responding policemen recovered a slug of undetermined caliber from the crime scene. - Wenna A. Berondo and Edwin Ian Melecio/BRP