Detention without trial

Having doubled, and then doubled again, the length they can hold innocent people without trial, Labour are back to wanting to extend it further. Let us remember everybody is innocent until proven guilty, or at least they where until Labour assumed power and changed things. Why do they need to hold people for such an inordinately long time. During the IRA campaigne of terror a mere seven days was considered enough. Still worried that the bones might not have had time to heal?