First, what date are you talking about?
(Western) Samoa has been under several different administrations, so it depends on when the event happened.
second; Was he a native Samoan or a foreigner? Some foreigners were registered in the embassy of their home country rather than the government of Samoa at that time?
Third; Where are you?
The Samoan Archive is held in Wellington NZ at Archives NZ. This contains the government records of all the administrations up to Samoan independence.
The present Samoan Government also holds copies of the documents.
American Samoa has its own records which are available there and in the Pacific Sierra region of NAARA, somewhere in California I think