The White-tailed deer, whitetail or Virginia deer (Odocoileus virginianus) is a common species of wild ungulate in the State of New Jersey and is also present through large parts of America from southern Canada to northern Venezuela. This type of deer is commonly used in American fiction to symbolize uncorrupted nature and innocence, although it is debatable if this is the case in Boardwalk Empire, where it is nonetheless featured prominently. As of "Georgia Peaches" all the deer seen in the series have been male (as evidenced by the presence of antlers) and created with CGI.
White-tailed deer appear in the woods near Hammonton, New Jersey in the pilot episode "Boardwalk Empire". The first one is at the side of the road and looks at the convoy headed by Davey Murdoch as the truck driven by Simon passes near it, its eyes reflecting the vehicle's lights in the dark of the night. The second one (if it is not the same) runs across the road after having made quite a noise in the forest and startles Al Capone, prompting him and Jimmy Darmody to kill the five members of Murdoch's convoy in an event that will be dubbed by the press as the Woods Massacre. Capone's behaviour is likely explained by his unfamiliarity with a wooden environment, as until that point he had worked only in Brooklyn and Chicago, while Darmody probably learned to distinguish wildlife from human made noise through his childhood hunting excursions with Nucky Thompson and his combat experience in World War I France.
Gillian Darmody's manouvres to push Jimmy near the Commodore and against Nucky Thompson include inviting him to "remember" how the Commodore took him to hunt deer as a kid. Jimmy corrects her and says that Nucky used to do it, not the Commodore. Nucky also remembers this well and sends Jimmy a statue of a hunter and his son looking at a killed deer as a wedding present when he senses that Jimmy is turning away from him. Jimmy chooses to place the statue in a closet ("21")
After Nucky is shot through the hand, he has a recurring nightmare where he walks into his office and finds a kid at his desk and a mortally wounded deer beneath it. After looking at the deer, the kid shoots him. ("Two Boats and a Lifeguard")
Deer are referenced a third time when Manny Horvitz and Mickey Doyle visit Jimmy at the Commodore's home. Manny, in line with Jewish religious practice, shows his disapproval at the Commodore's large collection of stuffed animals and sport hunting in general, retelling a time when a man brought a fresh killed deer to his butcher shop and asked him to cut only the head to make a trophy and disregard the rest of the body, adding that he didn't even shoot that deer but a friend of his did just so the man could have a hunting trophy without being a hunter. Doyle misses the point of the story and asks if deer are kosher, while Jimmy replies that he has eaten deer meat (venison). Manny insults Jimmy then saying that he probably hid "behind Papa" while he shot. ("Two Boats and a Lifeguard")