Why was there a concentration of serial killers in California during the 60’s/70’s?

Question

What caused this to happen?

Why were most of the documented 20th century serial killers American?

What behavioral “type”/“profile” leads to serial versus mass versus spree killer?

In: Other

Answer 1

Part of it is just that California is a very populous state, so has more of everything.

But also it’s believed that “copycat crimes” (people getting crazy ideas from TV) could be a factor.