= societies which in the past had well-developed police systems 'have' helps to emphasise these in comparison to those that have not, and gives a feeling of present relevance or interest. A little more context might give a clearer idea, having only the short sentence to go by. d
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Hasibul Alam it has been societies that have had a developed police systemIs this a complete sentence? If so, it should begin with a capital letter and end with a full stop. However, I suspect that it is a only fragment of a sentence.