Jim Gannon said his capture of a bank robbery suspect in Homewood on Friday, Sept. 23, was just luck.Gannon, chief investigator for the Cook County Sheriff's Merit Board, is a retired Homewood police officer and currently a Homewood reserve officer. He was walking home from the Metra station about 4 p.m. when he noticed news helicopters hovering over town.Then he saw about 15 police vehicles from various south suburban departments go past, and he began to think something serious had happened."As I approached Cedar Road, a tall male I did not recognize . . .