According to the Webster dictionary a widower is “a man who has lost his wife by death and has not married again”. Is this definition broad enough to encompass the case whereby a man kills his wife, since, in that case, he loses her by death as well?
From a purely logical perspective, this may be true. However, we have to agree on the meaning of “losing someone by death”. I can hardly see a murderer, who deliberately takes the life of her spouse, as someone who lost his wife. I consider a widower as someone who suffers a loss, whereas a murderer actively causes what could at most be said a “self-inflicted loss”.