A pair of incidents in Pontiac involving gunfire early Sunday morning are being investigated by the Oakland County Sheriff's Office. A 28-year-old Pontiac man told authorities he was robbed by an armed suspect on the 400 block of Ferry Street around 2:30 a.m. The man was walking home when he was approached by the suspect who demanded he empty his pockets of any belongings, according to a press release from the Sheriff's Office.