My mate was killed by a householder a few years ago. He was in someone's garden when the guard dogs (rotweillers) discovered him an alerted their Owner, the householder, who came out of the house to see what the dogs were barking at - he was accompanied by two adult friends (one being the householder's wife).
They found my mate quite easily, and first knocked him to the ground, then householder stabbed him through the heart four times with a garden fork whilst he two mates watched. The householder claimed that my mate, who was unarmed at the time, had in fact attacked him and his two friends so, as he feared for their lives, he had acted in self-defence. Of course, my mate couldn't disprove this because he was dead.
The jury found the housholder not guilty of murder or, in fact, of any offence.
So, as most of you say, if you get your story right, you can get away with murder.