What is the name and artist of this song?

I've scoured Google trying to find out what this song was for years and it's driving me nuts! This is a link to it from YouTube (http://www.youtube.com/watch?v=2jR6ER8zk0M). Many people attribute it to Enya, which it is not. I think it might be from the original Boondock Saints movie but from the clips of the soundtrack I've heard, nothing matches. And the information provided on the YouTube video is wrong. Can anyone help me? Thanks in advance!