there are a lot of avidences against him
1. his mother said that he used to get very angry, and has a temper problem.
2. he came home at the night before the day the found her dead.
3. she couldn't have killed her self just to get revenge upon him??? she had no reason to kill herself, and I don't think she the type of persons who can commit suicide.
4. he said he bought the poison ??
I think he killed her, I don't pity him, but I pity Anna, poor thing :(

i dont think he's that kind of man!! well atleast i hope not...

He obviously killed her.he left clues like breadcrumbs, a straight trail and he would do anything for Anna, including kill his wife

He totally did it. He was so sinister in prison and was able to blackmail his way out. Did you see the way that he treated O'Brien when he wanted her to shut up the little footman? He has a little bit of the Godfather in him...