There are at least three Norman bates'.

One is a hardcore band from jersey: http://www.myspace.com/normanbatesmetal

And the other one is a german jazz/funk/downtempo-rapper/singer, better known just as "Bates". He is currently working within his homebase "Zughafen", as well as artists like clueso, the rythm club or Makabu.
www.normanbates.de

Another one is a nu-metal / crossover band from Rakovník in Czech Republic. Check out their Bandzone profile. Read more on Last.fm. User-contributed text is available under the Creative Commons By-SA License; additional terms may apply.