Imagine that you find $1000 on the street. How much would you feel tempted to take it?
Imagine that you meet a person who has $1000 in their pocket. Assuming that you feel absolutely no empathy, how much would you feel tempted to kill the person and take their money? Let's assume that you believe there is almost zero chance someone would connect you with the crime -- either because you are in a highly anonymous situation, or because you are simply too bad at estimating risk.
It's possible to steelman that hypothetical to the threshold that yeah, killing someone for their money would be tempting. It wouldn't have much resemblance to real life after that however.
There are several other reasons not to kill someone for their money than empathy, so I'm not sure how your hypothetical illustrates anything relevant.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.