As we all know, in the old cannon, Alucard's mother, Lisa, was executed because she used medicine to alleviate the suffering of the sick and it was mistaken for witchcraft. Alucard witnessed her execution and her final words were: "do not harm humans. if you do nothing, then at least do them no harm for their's is already a hard lot."
Now then, we don't know exactly how old Alucard was at the time, but we do know he loved his mother. So, the question is: despite Lisa's final words, do you think that Alucard went on a rampage and kill humans to avenge his mother?
WHAT ARE YOUR OPINIONS?
Personally, I think he would have. Regardless of your age, losing a loved one is emotionally painful and if they were killed right in front of you, you become emotional and likely lose control of your emotions. Let's also not forget that Alucard is half-vampire and in such an emotional state, his vampiric instincts might over power his will.
So, yes I do think that after Lisa was killed, Alucard went on a rampage and slaughtered everyone how was there. I'm not saying that he didn't feel remorse afterward. I'm just saying that the lose of someone he loved so much would cause him to lose control of himself.