Because we also think he has a drug problem.

因为我们认为他有毒瘾
The addiction plus his anger issues

有毒瘾加上脾气暴躁
means that he probably lacks the social skills

说明他缺乏上学或是保住稳定工作
required to stay in school or hold down a steady job.

所需要的社交能力
Because brute force and humiliation are the hallmarks of his M.O.,

鉴于他作案手法的特点是暴力和侮辱
we believe his kills are somehow rooted in revenge.

我们认为他杀人的动机可能源于复仇
We think he may have been traumatically humiliated

我们认为他可能在不久之前
in some way in the recent past.

受过某种侮辱造成了心理创伤
Probably as an adolescent,

很可能是青少年时期
which makes this very personal to him.

人在那段时期会非常记仇
Now he's looking for payback.

现在他要报复
So why did this guy wait a whole year after his first murders?

他第一次杀人后为什么等了整整一年