I realize it might be a "natural"or "human" emotion, but that doesn't make it right.
I realize we aren't God, but we are asked to try to become godly in our responses to people. Having anger toward someone who just took their life is not a godly response.
When Christ was apprehended and betrayed by Judas, one of his followers cut off the ear of one of the mob. Christ restored the ear and told his followers that "you know not of what spirit thou art". Meaning, anger is of Satan, not God.
However you want to explain it, anger toward someone that just took there life is not of God.