This is why a horrible crime like rape is typically not punished as strictly as murder: if the penalty were the same, why not do away with the witness. Though the effect of the crime on the victim can last a lifetime, at least they will be alive.
FWIW this probably doesn’t make any sense in practice. Most rapes are done by people who think they will get away with it either because it’s very hard to catch or because they have sufficient social power. Now, these people are clearly huge pieces of shit, but they’re probably not going to decide to murder the victim to minimize legal risk just because the potential penalties if convicted are closer. Murder is much harder to get away with and social power is much less likely to save you. Also, people don’t like committing murder generally, even if they’re apathetic enough to commit rape. The proposed logic feels like it describes the world in which rapes are committed by scary men who randomly break into your house because they’re just criminals. Not to trivialize the unfortunate fact that the latter does happen and it’s very sad, but it’s relatively rare.
If someone "has sufficient social power" as you put it, to get away with such a crime, then why do you think they wouldn't be able to make a person "disappear"?
Say, we were talkingn about basically an organized crime figure who ended up running a corrupt state. If you were a victim, would you bet that nothing would happen to you if you made a criminal complaint, filed a lawsuit, or went to the media?
This scenario is not a "scary man who randomly breaks into your house" - that doesn't seem at all implicit in the parent comment.
maybe it would work for white collar crimes, sadly we don't really punish those at all.
Surely the penalty for murder would mean something if your business is murder, just like taxpayer bailouts affect your appetite for risk at an investment bank.
Or, as biztos brings up, mostly looked at criminals who weren't making a considered decision in the first place.
https://www.nap.edu/read/18613/chapter/7#132
Studies have shown that extremely harsh penalties have minimal deterrence effects compared to moderately harsh penalties. More specifically, they advocate for a response function with a gradually decreasing gradient. Unfortunately, they have no recommendations as to what makes for a "moderately harsh" penalty, and they even acknowledge that some studies have shown deterrence effects from policies such as California's 3-strikes law.
Briefly, a drug policy guy makes the case that "swift and certain" punishment with pretty usually not very severe outcomes does a lot better as deterrence than what we do now.
There's a lot to digest, and I don't think anyone is going to agree with all of it - he gores a lot of oxen. But it is meticulously researched and reasoned, and hard for this non-policy professional to argue with. Really worth at least borrowing at the library for folks who like grappling with reality at a policy level.
Mark was also a prolific blogger who died recently. I didn't know him, but did read his blog.
[1] https://www.amazon.com/When-Brute-Force-Fails-Punishment/dp/...
As an aside, something feels off about this example. Choosing to differ the penalties to incentivize not murdering the victim suggests that the murder outcome is less desirable, i.e. the crime is more horrible. The argument implicitly assumes that murder is the more horrible crime while making a case for why the punishments differ. Given that punishments are generally expected to be in proportion to the horribleness of the crime that assumption suggests that the punishments would differ to begin with.