Has Malone had any problems with his ears???
I met a girl along time ago & she told me her GSD had an ear infection, & the infection got into the brain & started to kill the brain & the dog went vicious one day & it kept getting worse until the dog tried to kill a person. Thats when they found out what an ear infection can do to a dog.

So check his ears to see if hes ok.. I don't think its normal for a dog to suddenly become vicious.