> it’s more that there are a lot of ways to kill people and advances in technology and dissemination of information is going to bring more of them within reach of the average homicidal person.
I don't buy this.
The "average" homicidal person generally isn't that capable. And everything you mentioned requires at least above average skill levels in quite a few different areas.
Yes, a smart homicidal maniac may have a lot more options, but most homicidal people simply aren't that smart.