he actually has a compulsion

但事实上只是一种难以压制的犯罪冲动
which is the real reason behind them.

这才是他的真正动机
And this has resulted in a

从而导致
rapid escalation of his M.O. and his timeframe.

他犯罪模式恶化犯罪间隔缩短
He's become more efficient and more violent.

他愈加迅猛愈加暴力
This makes him unpredictable and even more dangerous.

因而他难以预测极度危险
He focuses on victims who are fragile and vulnerable

他先锁定身心脆弱者为被害人
and then creates relationships with them.

然后与他们建立联系
You need to look for someone who has close access

你们需要留意那些能轻易接触到
to people in need.

需要帮助的人的人
He may work in a government aid office or a community center.

他或许在政府援助部门或社区中心工作
His coworkers will describe him...

他的同事会说他...