A Ugandan man who lives in Saco has been convicted of helping arrange a scam marriage so another man could become a legal permanent resident of the United States. Federal prosecutors say 35-year-old Ronald Serunjogi was convicted this week of helping another Ugandan man who had overstayed his tourist visa pay a Lewiston woman who agreed to marry the other man so he could became a lawful permanent resident. Serunjogi assisted that man, Sampson Sengoonzi, in preparing documents to immigration authorities in support of Sengoonzi’s application. Immigration authorities detected the fraud, denied Sengoonzi’s application and referred the matter for criminal investigation. Sengoonzi was previously convicted and sentenced for his role in the scheme and has been ordered deported. Serunjogi faces up to five years in prison at sentencing.