I personally put a high price on family loyalty / confidentiality . . .
Suppose your brother had murdered, not his girlfriend, but his wife – i.e. your own sister-in-law. Would your answer be different? Would it depend on how you felt about your sister-in-law? Or about her children – your nephews and nieces?
Suppose he had murdered his sister (and yours)?
Suppose he had murdered your wife?
I suspect your decision here – anyone’s decision – would depend not just on your relationship with the perpetrator, but also on your relationship with the victim.
What you do for your brother by you silence is to keep him out of prison. What you do for the victim, if you speak out (or entrap) is ensure that her killer is called to account.
But is our obligation to the murder victim (and to their family and friends) limited as we ourselves are distanced from the murder victim? Can we say that my obligation to call my sister’s killer to account is greater than my obligation to call my sister-in-law’s killer to account, which in turn is greater than my obligation to call to account the killer of a casual acquaintance, or a complete stranger, or someone who lives far away and in another country?
I would be concerned about this. In general we regard tribalism – treating the interests of the tribe and its members as the paramount ethical consideration - as a curse, and we struggle to transcend it. But it seems to me that we succumb to tribalism if we concede that my obligations to the perpetrator of a crime, and to the victim of the same crime, vary according to how closely each of them is connected to me, and that my decision should ultimately be dictated by the closeness of one of them to me, and the relative distance of the other.
I’m much more comfortable with an analysis which says, no, keeping silent to protect my brother is not ethical
, but it is understandable
. I simply lack the moral strength to do what I ought, in the face of my close connection to my brother.
(Let’s face it; I’ve done unethical things for considerably less compelling reasons in the past.)