For all the people asking about how Richard knows who abused his brother
The film is set in 2004, the torture of Anthony occured 8 years earlier which would of course have been 1996, After the funeral Richard wouldn't have had a clue what had happened, that's why he didn't deal with these scumbags straight after, he waited 8 years!!
I think Richard has such a in depth knowledge of what went on is because he's spent the last 8 years actually investigating and finding out every detail of what happened to his brother, he'd probably been stalking and watching these guys for years on end before he finally had all in the information he needed and made his move.
Men are guilty of all the good they do not do.