ASP.NET MVC 4 Error Handling

Okay, so I am trying to get my controller to go to the Error.cshtml under the Shared folder on error. I've got the filter configured at startup:

Global.asax

protected void Application_Start()
{
    ...
    FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
    ...
}

FilterConfig.cs

public static void RegisterGlobalFilters(GlobalFilterCollection filters)
{
    filters.Add(new HandleErrorAttribute());
}

HomeController.cs

[HandleError(View = "Error")] <---- I have the HandleError attribute
public class HomeController : Controller
{
    IDbConnection _connection = new SqlConnection(ConfigurationManager.ConnectionStrings["DefaultConnection"].ConnectionString);

    [Authorize]
    public ActionResult Index()
    {
        // get the users current events
        try
        {
            ViewBag.UserEvents = _connection.Query<MyEvents>("select ...)", new { });
        }
        catch (Exception ex)
        {
            throw new HttpException(500, ex.Message);
        }

        return View();
    }
    ...
}

And so when the Index method is throwing an exception because I didn't open the connection, it just gives me the default ASP.NET exception page. What did I miss here?

Thanks!