Psychopathy is a combination of genetics and environmental factors. Genetics does not cause this condition. You can have the genes associated with higher prevalence but that does not mean you will have it.
This is why eugenics for behavioral or personality factors is irrelevant.

Also these are not necessarily hereditary but likely are common mutations that will persist in the gene pool regardless if current people with said gene are sterilized.

Genetic research, not to sound pretentious, is largely misunderstood.

When a study says genetics are 30%. It means genetics account for 30% of the variance.

The variance is not "effect". Or how much a gene contributed to the trait.

It's a bit more complicated. But to make a simple example.

Let's think of height.

Let's say someone has a gene(s) for being tall.

But the person grew up malnourished. It doesnt matter, the kid won't be tall. But will the kid be taller than other malnourished kids with out the gene. ? Probably. But it's hard to say by how much.

Will the kid be taller than other kids that werent malnourished.

Maybe. Maybe not.
If extreme malnourished, the answer is no.

Ultimately the environment determines how much effect a gene(s) can determine a trait.

That's why you can't measure a general effect % from a gene(s).

Instead we measure how much variation in a group of people with a given trait is predicted by a gene.

"The wiggle room". A gene is best thought of as the limits of a trait. Each extreme.

When it's in optimal environment to be expressed and when it's in the most restricted environment to be expressed.

Even in average environments, genetics still usually doesn't account for more that 30-40% of the variance for people who score within 1 standard deviation of the mean/average of a trait. And that number declines the farther you get from the mean.

And also most genetics don't score that high. Very few are as high as 30%.

https://en.wikipedia.org/wiki/Genetic_variance