Chicago police are looking to identify three people suspected in a downtown knife attack two weeks ago.The men battered a 27-year-old man with a knife Sept. 15 in the 400 block of North Michigan Avenue about 12:30 a.m.Police described the suspects as three Hispanic males between the ages of 15 and 25. They are about 5 feet 7 to 5 feet 11 and weigh between 140 and 200 pounds.Anyone with information about the assailants can leave an anonymous tip at cpdtip.com.