The function for making it move to a deleted table.

function_proccess_deleted.sql

CREATE OR REPLACE FUNCTION process_deleted() RETURNS TRIGGER AS $$
  BEGIN
    IF (TG_OP = 'DELETE') THEN
      EXECUTE 'INSERT INTO deleted_' || TG_RELNAME || ' VALUES(($1).*)' USING OLD;
      RETURN OLD;
    END IF;
    RETURN NULL;
  END;
$$ LANGUAGE plpgsql;