SYDNEY (AP) — Police arrested four people during a series of raids Wednesday in connection with the slaying of a civilian police worker, which officials have said they believe was linked to terrorism. Police believe the killing was politically motivated and therefore linked to terrorism, though they say Jabar's specific motivations remain unclear and he has not been linked to any terror group. Police don't know what the association might be between Jabar and the men who were arrested on Wednesday, and Deputy Commissioner Catherine Burn declined to say what part officials believe they played in last week's shooting beyond allegedly having knowledge of the attack. Neil Gaughan, acting deputy commissioner of the Australian Federal Police, confirmed reports that Australian police were working with officials in Turkey to locate Jabar's sister, who is believed to have flown to Istanbul shortly before Cheng was killed.