Do you think Brian killed…

Dexter’s adopted mom Doris?

Everyone is talking about that Brian 100% killed Harry (and Possibly Michael C. Hall’s actual father), but is this possible?

All we hear is a very vague cancer diagnosis, but considering Brian is the smartest killer ever who ever lived, he could have easily made a cancer patient’s death look natural.

It’s also highly probably that Brian kills Camilla’s husband Gene, Captain Matthew’s wife, and was heavily involved in planning 9/11. Thoughts?