Police in Florida believe they may have caught a potential serial killer following the arrest of an 18-year-old man. Law enforcement officers arrested Omarion Ivory from Port St Lucie for the killing of 67-year-old Francis Gennace on Wednesday, according to the Port St. Lucie Police Department. Ivory was served the arrest warrant at St Lucie County Jail where he was already being held after a previous arrest on September 20.