Officer of law enforcement
The law must be upheld and the law enforcer is the one that has to do it. The tititle this man hold(there are almost no women in this professiorn during the 1920's) could be Constable,Detective, Agent, Sheriff, Marshall or Gendarme depending upon where in the world the games takes you.
Some law enfocers are plain uniformed patrolmen others are civilian dressed detectives.The situation for the individual law enfocer depends upon which surrunds he or she operates. In the game of CoC it is often the ones having to spend their time in backwater communities that fid themselves facing the full horrors of what should not be. Simple investigations or rutine patrols now and then leads the law enfocers into encounters with the unknown.