Er in fact it was put to me as as an option by Superintendent  that this could be, if this could be done  er at the time er  if I recall  one of the reasons erm  that we weren't able to do it in such a way  was that there are numerous  exits to the block of flats and each exit would have had to be covered by at least two armed officers  we only only had in the region of twenty five officers available to us at that time in the  police who were authorised to be armed  and to maintain such a surveillance, erm not only would be  very costly in the terms of the number of officers.