Have seen the show End of Spear. It is a very good movie and there's a book by the same title too (I heard the book is much better than the movie). It is about 5 American missionaries who were killed by Aucas and some of the killed missionary family members later came to live with the Aucas and convert them. They still maintain close relationship even now (imagine the son ie Steve Saint whose father was killed by Mincaye (an Auca) calls him father).
The story is so powerful that I think it would be a good gift to give someone (whether they are born again or not). I do think its a good witnessing tool. That's why I'm putting it here instead of the book or movie forum
There's an earlier story and documentary (Through/Beyond the gates of Splendour) that is relating to this as well.
I'm attaching some websites so that you can have a better idea what the story is about.http://en.wikipedia.org/wiki/Steve_Saint
PS: I suggest getting the book as the book is more accurate and has so much more. The movie had to change quite a fair bit so that it is more interesting etc