Shooter spent a year planning Munich attack

Investigators looking into Friday's mass shooting in Munich say the gunman spent more than a year preparing his attack.Bavarian investigator Robert Heimberger said the 18-year-old shooter, identified only as David S., visited the site of a previous school shooting in the German town of Winnenden and took photographs.He said the shooter, who likely got his illegal weapon through the internet's "dark net" market, was an avid player of first-person shooter video games, including "Counter-Strike: So