Why are there fewer serial killers now than there used to be?

I was at an author-reading of a book about female serial killers. Curiously, the ones covered in the book all had pretty amazing victim counts. From a dozen to really large numbers.

I thought, since serial killers are caught essentially at random, shouldn't the victim count follow a normal curve? Some caught after one or two; many at some median point in their career; a few after large numbers?

And I thought again, perhaps we don't believe women can be serial killers and so overlook them, allowing their careers to flourish over years or decades? Indeed the book listed several famous cases where the police, judge or jury simply refused to believe a woman had done all that.

Moral: there are possibly many women serial killers out there, undetected. A whole normal distribution of them.

From https://lemire.me/blog/2023/06/03/science-and-technogy-links...

I thought it was interesting enough to post.

I had previously read that increased freedom, the interstate system, Vietnam trauma, and cable news coverage were all factors in the rise, or perceived rise of serial killers.

Fewer serial killers, but more mass killers, for a net increase in victims.