After reading your question and about your family the circumstances you related has many similarities to my life.  My mother-in-law moved in with us after she was diagnosed with AD about ten years ago.  She was retired college professor and lawyer and we were always concerned about the drastic changes which would come with this illness.  She is in what I would consider the moderate/severe stage with need for constant supervision or she will wonder off and assistance with all self care needs.  Aggressive/violent behavior has been mild thus far with more aggressive behavior being demonstrated verbally, more out of frustration than aggressiveness.  She attends a day respite program which was been wonderful for her and for us to realize that this disease looks very different for each person who is diagnosed with it.    Good luck to you and your family as you travel this journey with him.