And not just regionally but over time.

而且在空间和时间上都很分散
The first one dates back to the '60s.

第一起发生在60年代
- The 1960s? - Yeah.

-20世纪60年代吗 -对
That would put the guy, what, in his 70s?

那么这个凶手现在都70多岁了吧
- Yeah, or his 60s. - Yeah, I...

-对或者60多 -我
- I don't know. - Well, look at the methodology.

-不好说 -看看这作案手法
Toxicology reports, some cases the killer drugged his victims.

毒理报告记载有些受害者被凶手下了药
- With what? - Well, they couldn't tell for sure.

-什么药 -他们也无法确定
But by drugging them,

但下了药之后
the killer removes his need to overpower them.

凶手就不用靠力气制服他们了
Here he used a tree branch to do the heavy lifting.

这次他用树枝做杠杆来抬重物
In Sacramento he lit a family on fire.

萨克拉门托那次是放火烧