But the area is guarded by the Secret Service and Chicago police.

VOA: special.2009.01.12

He trains police and secret service members to try to figure out cues to honesty and dishonesty.

他培训警察及情报局人员,试图找到诚实和撒谎的线索。

耶鲁公开课 - 心理学导论课程节选