sicko

noun

1. 从病态行为取乐的人；（精神）变态者
   a person who gets enjoyment from doing strange and cruel things
   1. child molesters and other sickos
      对儿童进行性骚扰者及其他变态狂

1. Only a sicko could commit a crime like that.
   只有脑子有毛病的人才会犯那样的罪。