Rao Anwar went into hiding after he and other officers killed Naqeeb Ullah earlier this month and then tried to cover it up, saying that Ullah was a Taliban militant killed in a shootout.
An investigation later found that Ullah had no ties to the militants. The motive for the Jan 13 killing remains unclear.
Today, some 3,000 protesters from Ullah's tribe vowed to continue their sit-in until Anwar is arrested. Anwar has been relieved of duty and barred from leaving Pakistan. Police have carried out several raids while looking for him.