enforcer vs trigger person

enforcer

noun
  • The member of a group, especially of a gang, charged with keeping dissident members obedient. 

  • A hired strongman, especially working for the underworld. 

  • One who enforces. 

  • A player who physically intimidates or confronts the opposition. 

trigger person

How often have the words enforcer and trigger person occurred in a corpus of books? (source: Google Ngram Viewer )