ROBIN TRIMARCHI rtrimarchi@ledger-enquirer.com Emily Martiny, 9, rides the mechanical bull at the Ark-in-th-Park Halloween at Britt David Park Wednesday. The Fox Elementary fourth-grader was one of about 3,500 people expected at the annual event, sponsored by Britt David Baptist Church, and co-sponsored by business throughout Columbus. 3,000 pounds of candy was donated and handed out at the various games and inflatables set up on the ballfield grass. 10.31.12 ROBIN TRIMARCHI