Consequentialism doesn't necessarily dictate that it is morally right to execute an innocent person as a deterrent.
But, yes, if I value the results of that deterrent more than I value that life, then it does.
I expect this is what you meant in this case.
Just to pick a concrete example: if the deterrent execution saves a hundred innocent lives over the next year, and I value a hundred innocent lives over one innocent life, then consequentialist ethics dictate that I endorse the deterrent execution, whereas non-consequentialist ethics might allow or require me to oppose it.
Would you say that allowing those hundred innocent people to die is justice?
If not, then it sounds like justice is equally missing from non-consequentialist ethics, and therefore justice is not grounds for choice here.
If so... huh. I think I just disagree with you about what justice looks like, then.
This makes it seem to me that Consequentialism is totally subjective: whatever produces the result I personally value the most is what is morally right.
So if I don't value innocent human lives, taking them reaps me great value, & I'm not likely to get caught or punished, then Consequentialism dictates that I take as many innocent human lives as I can?
Will Crouch has written up a list of the most important unsolved problems in ethics:
The Practical List
What’s the optimal career choice? Professional philanthropy, influencing, research, or something more common-sensically virtuous?
What’s the optimal donation area? Development charities? Animal welfare charities? Extinction risk mitigation charities? Meta-charities? Or investing the money and donating later?
What are the highest leverage political policies? Libertarian paternalism? Prediction markets? Cruelty taxes, such as taxes on caged hens; luxury taxes?
What are the highest value areas of research? Tropical medicine? Artificial intelligence? Economic cost-effectiveness analysis? Moral philosophy?
Given our best ethical theories (or best credence distribution in ethical theories), what’s the biggest problem we currently face?
The Theoretical List
What’s the correct population ethics? How should we value future people compared with present people? Do people have diminishing marginal value?
Should we maximise expected value when it comes to small probabilities of huge amounts of value? If not, what should we do instead?
How should we respond to the possibility of creating infinite value (or disvalue)? Should that consideration swamp all others? If not, why not?
How should we respond to the possibility that the universe actually has infinite value? Does it mean that we have no reason to do any action (because we don’t increase the sum total of value in the world)? Or does this possibility refute aggregative consequentialism?
How should we accommodate moral uncertainty? Should we apply expected utility theory? If so, how do we make intertheoretic value comparisons? Does this mean that some high-stakes theories should dominate our moral thinking, even if we assign them low credence?
How should intuitions weigh against theoretical virtues in normative ethics? Is common-sense ethics roughly correct? Or should we prefer simpler moral theories?
Should we prioritise the prevention of human wrongs over the alleviation of naturally caused suffering? If so, by how much?
What sorts of entities have moral value? Humans, presumably. But what about non-human animals? Insects? The natural environment? Artificial intelligence?
What additional items should be on these lists?