U ndeniable duty, undefendable crime
It was predetermined. There was no choice in the matter.
Percival Dumbledore did not hate Muggles, but he would kill them. Perhaps he would have killed the men who did this to his little girl in any case, but these were boys. He could forgive them – to a degree. They knew not what they did; he could allow them to live.
But that is not how things are done. It could not even be a crime, once, because it was expected and must be done in any case.
It could have been a trap set by his enemies it was so clever and inescapable.
He would have done better by his family to stay and help care for Ariana and support Kendra and the boys. It was not an option.
Nor would he hide it or purchase his freedom. Or even use their actions as his excuse. Because it might work, and he could not let that happen. Muggles…deserved better than that, and he had business only with three of them. He would do his duty. He would kill boys he did not hate and go quietly to prison.
That was just like a Dumbledore: old-fashioned enough to avenge the family honor, liberal enough to sully the family name.