线人

yī míng xiàn rén wèn wǒ zuì hòu yī cì mù jī tā de dì fang

一名线人问我最后一次目击他的地方。

An informant tipped me off as to where he was seen last.

mù jī zhě shì lián bāng diào chá jú chū qián gù yòng de xiàn rén

目击者是联邦调查局出钱雇用的线人。

The witness was a paid informant for the FBI.