Is it a gravely sinful act to give shelter to a criminal wanted by the State?
Under normal circumstances, the above mentioned outline of events would constitute a mortal sin, if someone were to give shelter to someone fleeing from justice.
As Catholics, we must try to uphold the law as best as possible. But the above scenario does not do that.
The threshold of the three conditions for a serious sin are met here, for someone hiding (giving shelter) to a fugitive from the law:
So what kind of Sins are Mortal?
In order for a sin to be mortal, it must meet three conditions, for the individual concealing someone hiding from the law:
Mortal sin is a sin of grave matter
Mortal sin is committed with full knowledge of the sinner
Mortal sin is committed with deliberate consent of the sinner
This means that mortal sins cannot be done “accidentally.” A person who commits a mortal sin is one who knows that their sin is wrong, but still deliberately commits the sin anyway. This means that mortal sins are “premeditated” by the sinner and thus are truly a rejection of God’s law and love.
The first condition, that a mortal sin is of grave matter, means that certain premeditated offenses against God are more severe than others. We know that some sins are graver than others (e.g. it is a graver sin to murder someone than to lie to someone). St. John tells us, “If anyone sees his brother sinning, if the sin is not deadly, he should pray to God and he will give him life. This is only for those whose sin is not deadly. There is such a thing as deadly sin, about which I do not say that you should pray. All wrongdoing is sin, but there is sin that is not deadly.” (1 John 5:16-17). Thus St. John distinguishes between mortal and venial sin. Jesus also warns us that “Anyone who does not remain in me will be thrown out like a branch and wither; people will gather them and throw them into a fire and they will be burned” (John 15:6).
Unless there is extenuating circumstances that could possibly diminish a person’s culpability, which I do not see here, it would be sinful for someone to give shelter to a criminal fleeing from justice!
It is not up to individuals to decide of determine if the offender is not fully accountable for the crime?
Once arrested, at least in most countries, the perpetrator of a serous crime and the crime itself would have to be analyzed as to what were the circumstances of a particular murder or accidental killing. In any case the individual is guilty of manslaughter. Hiding him would get you in a serious situation with the law.
Best to encourage him to hand himself over.
The Church, mediated by the authority invested in the successor of Peter, can bind us in conscience on defined and infallible matters of faith and morals, but what of human law, those matters of directives and discipline, that are at times all-too fallible? Is it always a sin to skirt around the law, and might we do so in good conscience? Saint Thomas Aquinas asks this very question (I-II, q. 96, a. 4), and the principles he offers will help guide our own decisions, as we make our way ‘by the tangle of our wits’, as More advised Roper.
Aquinas defines law as an ‘ordinance of reason, promulgated by him who has authority over community, for the common good’ (I-II, Q. 90, a. 4). Human law, as it is based on reason, ultimately has its binding force from the natural moral law, in turn defined as ‘the rational creature’s participation in the eternal law’. So law binds not from its own authority but from God’s, and we are bound to obey the law insofar as it carries the authority of God.
Hence, if any law violates the law of God – the natural or divine law – then not only does it not bind in conscience, but we are rather bound to disobey such laws, at least by passive resistance (such as refusing to participate in abortion or euthanasia), and, if push comes to shove, to die a martyr rather than follow them, as did the first Christians of Rome, as did Thomas More himself, and as did countless witnesses against all the anti-Christian totalitarian regimes. - The Limits of Law and Obedience