Mo. Rev. Stat. § 252.068: Arrest powers of certain conservation department employees.

When there is reasonable grounds to believe that a person has committed or is in the process of committing a violation of the laws or rules and regulations pertaining to wildlife and forestry resources of the state, any commission or department employee who has been trained and certified as an investigative assistant by the director may:

(1) Detain the person in a reasonable manner and for a reasonable length of time for the purpose of investigating and reporting such a violation to law enforcement officers; and

(2) Contact law enforcement officers and assist with criminal proceedings against such person.