user-1: Not saying I have bodhicitta, one assumes I would know the answer if I did, but we can all emulate enlightening beings.
What is the best way to respond to an nominally (nothing like that is innate) evil person doing evil (whatever you think amounts to that enough to at know not only that they should be stopped but that a lot hinges on it for other people) to get what they want?
We vow to save all sentient beings: can we postpone it for some? Do we say "a Buddha would help you in your next life, but I cannot"?
I suppose the answer is just to offer help to others first: after-all, we are all said to have undergone countless, trillions by trillions of lives, so no one life can be blamed for how it has suffered. But what if the evil doer turns to you for a better rebirth, after or even before their evil actions?

user12953: I think you are under a misapprehension about bodhicitta, as something you can either have or not have. It wells up in all beings, because it is a deep part of the nature of minds to recognise other minds, and as we wish for our own wellbeing, to wish for their wellbeing. It is an intrinsic and spontaneous quality, which only layers of bad experiences or being misled can cause us to ignore. Bodhicitta can be cultivated, practiced, by contemplating this wish for the benefit of all beings, and prioritising it as a motivation for action in life. To put it at the centre of our causes for action, is to walk the bodhisattva path.
The Buddhas teaching is very demanding:

"Monks, even if bandits were to savagely sever you, limb by limb, with
a double-handled saw, even then, whoever of you harbors ill will at
heart would not be upholding my Teaching" -Kakacupama Sutta

First of all, note this is about ill-will, not action and reaction, but how the bandits actions affect your mind. Forgiveness, doesn't mean no consequences. You don't have to help push the saw, you have to attend to your mind, and use it for the benefit of all beings.
Bear in mind also, this is directed at full-time spiritual practicioners, placing attaining awakening above all other priorities. Householders, lay-Buddhists, have other duties and priorities which the teachings are clear they should not shirk - consider how a farmer doing pest-control helps provide grain for monks to eat (but a skillful farmer needs less pest-control).
There is also the Buddhist idea of a 'wheel-turning monarch' or ruler or emperor: someone worldly who must manage an army and deliver justice, but does so in a way that creates opportunities for many more to become awakened. See for example the Cakkavatti sutta. Emperor Ashoka is surely such a one, the first ruler to unify India, although he was said to have given up war & converted to Buddhism after the particularly bloody and brutal military campaign involved. He did bot then abolish that military though, but sought to make violence less likely.
The Angulimalia Sutta concerns the conversion and awakening of a bandit that wore a necklace of human fingers and had murdered likely at least 200 people personally as a religious task (see the 'thuggee cult' for Indian cultural background on how this much earlier practice might have worked). Shown the true nature of things, Angulimalia ceased to cause suffering, and he was protected from families of his victims by the sangha, although he would still have to face the karma his actions had generated.
The koan of Nansen kills the cat generates a lot of controversy, which I think that linked commentary does a good job of picking through. An insightful point I've heard about the cat, is that they are very murderous of mice - yet humans very much need to not allow mice populations to grow unchecked (eg, mouse plagues, where mice also suffer). So a monk asks, should we keep a murdering cat? Nansen acts like the cat: You don't want this pest-cat? There, done. Happy? Having a cat is a choice like this, it's not a perfect choice, but we make a choice. The cat is not a monk. But like a farmer, like a monarch, it can be skillful.
In life we face dilemmas, we must decide who to help and who not. But don't make this a practice of just making endless agonising lists for and against why - that won't 'save the cat'. Put bodhicitta at your centre, know the taste of liberation, and the answer will come, while it can still make a difference, from paying attention to the qualities of this very moment. Make your mind into a diamond sword of wisdom, and you will know whether to kill or save the cat, for the benefit of all beings.
People don't set out to be evil. That word has special baggage because of it's importance in Christian theology, so it's worth thinking about how to interpret it, discussed here: The dark side of philosophy?. There is a saying "We are punished by our sins, not for our sins", that can help us understand evil-doers harm themselves, harm their own minds, and fundamental cure is in showing them the true nature of things, not telling them what to feel (though constraining their capacity to harm is likely a priority). That is recognising their Buddha nature, their intrinsic capacity to awaken to things as they are.

-1: <p>Not saying I have bodhicitta, one assumes I would know the answer if I did, but we can all emulate enlightening beings.</p>
<p>What is the best way to respond to an nominally (nothing like that is innate) evil person doing evil (whatever you think amounts to that enough to at know not only that they should be stopped but that a lot hinges on it for other people) to get what they want?</p>
<p>We vow to save all sentient beings: can we postpone it for some? Do we say &quot;a Buddha would help you in your next life, but I cannot&quot;?</p>
<p>I suppose the answer is just to offer help to others first: after-all, we are all said to have undergone countless, trillions by trillions of lives, so no one life can be blamed for how it has suffered. But what if the evil doer turns to you for a better rebirth, after or even before their evil actions?</p>
 12953: <p>I think you are under a misapprehension about bodhicitta, as something you can either have or not have. It wells up in all beings, because it is a deep part of the nature of minds to recognise other minds, and as we wish for our own wellbeing, to wish for their wellbeing. It is an intrinsic and spontaneous quality, which only layers of bad experiences or being misled can cause us to ignore. Bodhicitta can be cultivated, practiced, by contemplating this wish for the benefit of all beings, and prioritising it as a motivation for action in life. To put it at the centre of our causes for action, is to walk the bodhisattva path.</p>
<p>The Buddhas teaching is very demanding:</p>
<blockquote>
<p>&quot;Monks, even if bandits were to savagely sever you, limb by limb, with
a double-handled saw, even then, whoever of you harbors ill will at
heart would not be upholding my Teaching&quot; -<a href="https://www.accesstoinsight.org/tipitaka/mn/mn.021x.budd.html" rel="nofollow noreferrer">Kakacupama Sutta</a></p>
</blockquote>
<p>First of all, note this is about <em>ill-will</em>, not action and reaction, but how the bandits actions affect your <em>mind</em>. Forgiveness, doesn't mean no consequences. You don't have to help push the saw, you have to attend to your mind, and use it for the benefit of <em>all</em> beings.</p>
<p>Bear in mind also, this is directed at full-time spiritual practicioners, placing attaining awakening above all other priorities. Householders, lay-Buddhists, have other duties and priorities which the teachings are clear they should not shirk - consider how a farmer doing pest-control helps provide grain for monks to eat (but a skillful farmer needs less pest-control).</p>
<p>There is also the Buddhist idea of a 'wheel-turning monarch' or ruler or emperor: someone worldly who must manage an army and deliver justice, but does so in a way that creates opportunities for many more to become awakened. See for example the <a href="https://suttacentral.net/dn26/en/sujato" rel="nofollow noreferrer">Cakkavatti sutta</a>. Emperor Ashoka is surely such a one, the first ruler to unify India, although he was said to have given up war &amp; converted to Buddhism after the particularly bloody and brutal military campaign involved. He did bot then abolish that military though, but sought to make violence less likely.</p>
<p>The <a href="https://www.accesstoinsight.org/tipitaka/mn/mn.086.than.html" rel="nofollow noreferrer">Angulimalia Sutta</a> concerns the conversion and awakening of a bandit that wore a necklace of human fingers and had murdered likely at least 200 people personally as a religious task (see the '<a href="https://en.wikipedia.org/wiki/Thuggee#History" rel="nofollow noreferrer">thuggee cult</a>' for Indian cultural background on how this <em>much</em> earlier practice might have worked). Shown the true nature of things, Angulimalia ceased to cause suffering, and he was protected from families of his victims by the sangha, although he would still have to face the karma his actions had generated.</p>
<p>The koan of <a href="https://www.rzc.org/news/nansen-kills-the-cat/" rel="nofollow noreferrer">Nansen kills the cat</a> generates a lot of controversy, which I think that linked commentary does a good job of picking through. An insightful point I've heard about the cat, is that they are very murderous of mice - yet humans very much need to not allow mice populations to grow unchecked (eg, <a href="https://en.wikipedia.org/wiki/Mouse_plagues_in_Australia" rel="nofollow noreferrer">mouse plagues</a>, where mice also suffer). So a monk asks, should we keep a murdering cat? Nansen acts like the cat: You don't want this pest-cat? There, done. Happy? Having a cat is a choice like this, it's not a perfect choice, but we make a choice. The cat is not a monk. But like a farmer, like a monarch, it can be skillful.</p>
<p>In life we face dilemmas, we must decide who to help and who not. But don't make this a practice of just making endless agonising lists for and against why - that won't 'save the cat'. Put bodhicitta at your centre, know the taste of liberation, and the answer will come, while it can still make a difference, from paying attention to the qualities of <em>this very moment</em>. Make your mind into a diamond sword of wisdom, and you will know whether to kill or save the cat, for the benefit of all beings.</p>
<p>People don't set out to be evil. That word has special baggage because of it's importance in Christian theology, so it's worth thinking about how to interpret it, discussed here: <a href="https://philosophy.stackexchange.com/questions/2901/does-philosophy-have-a-dark-side/89227#89227">The dark side of philosophy?</a>. There is a saying &quot;We are punished by our sins, not for our sins&quot;, that can help us understand evil-doers harm themselves, harm their own minds, and fundamental cure is in showing them the true nature of things, not telling them what to feel (though constraining their capacity to harm is likely a priority). That is recognising their Buddha nature, their intrinsic capacity to awaken to things as they are.</p>
