Wyo. Stat. § 7-8-101: Arrest by private person.

(a) A person who is not a peace officer may arrest another for:

(i) A felony committed in his presence;

(ii) A felony which has been committed, even though not in his presence, if he has probable cause to believe the person to be arrested committed it; or

(iii) The following misdemeanors committed in his presence:

(A) A misdemeanor theft offense defined by W.S. 6-3-402; or

(B) A misdemeanor property destruction offense defined by W.S. 6-3-201.