particeps criminis
/ˌpɑːtɪsɛps ˈkrɪmɪnɪs/Law
noun
An accomplice or partner in crime; an accessory.
Origin
Mid 17th century; earliest use found in Edward Coke (1552–1634), lawyer, legal writer, and politician. From post-classical Latin particeps criminis from classical Latin particeps participant, accomplice + crīminis, genitive of crīmen crime.