Sadly, I was recently faced with a situation like this with my own brother. I don't want to go into details, but it was a very serious, dangerous crime/situation. I will never forgive him for putting his family's lives in danger and would've, after pleading with him to turn himself in, turned him in myself. My life would've immediately been threatened, but so be it.
Lucky for him, he had already run and so when the fugitive task force raided my place looking for him (which grates me even to this moment), I had nothing to tell. He did turn himself in, eventually.
I pray (really) that none of you ever have to face that situation. Ever.
Edit: I can't believe I actually typed that! Oh well, it's a matter of public record, anyway.
Lucky for him, he had already run and so when the fugitive task force raided my place looking for him (which grates me even to this moment), I had nothing to tell. He did turn himself in, eventually.
I pray (really) that none of you ever have to face that situation. Ever.

Edit: I can't believe I actually typed that! Oh well, it's a matter of public record, anyway.