Simplify the following text for a Grade 18 native English-speaking person.
Original: Killings , arrests , and deportation of Serbs and Jews was a regular duty of FrancetiÄ 's henchmenâ '' based and justified by the official Ustashe policy which demanded the total extermination of Jews and the murder ( 1\/3 ) and\/or expulsion ( 1\/3 ) and\/or forced conversion ( 1\/3 ) to the Roman Catholicism of the ethnic Serbian Orthodox population in Bosnia and Herzegovina .
Simplified: Killings , arrests , and deportation of Serbs and Jews was a regular duty of FrancetiÄ 's henchmen - based and justified by the official Ustashe policy which demanded total extermination of Jews and murder , expulsion , and conversion to the Roman Catholicism of Serb population in Bosnia and Herzegovina .