Often it is, but the death penalty isn’t the only thing affecting it - if it did, USA would not be at such a high of a spot for intentional homicides (#55) as most states have the death penalty as well.

For reference, Japan is at spot 196 out of 207 when you sort by victims per 100000 inhabitants.

Which also results in very few people getting the death penalty - just 3 people were executed in 2022, and none last year. US executed 18 and 24.