Vigilante (noun)

A member of a self-appointed group of citizens who undertake law enforcement in their community without legal authority.

Origin:

Mid 17th century: from spanish, literally "watchman", from vigilar "to watch".

Examples:

1. The town was plagued by a group of vigilantes who took the law into their own hands.
2. He was falsely accused of a crime and hunted by a vigilante group.
3. The vigilante group was known for their brutal tactics and lack of due process.
4. Vigilante justice can be dangerous and often leads to more harm than good.
5. The police were investigating the vigilante group, who had been intimidating local residents.