The bodycam videos of the beat cops show what little security there was around the AGR building. The beat cops were the ones that were doing crowd and traffic control and were diverted in the last few minutes to look for Crooks.
The locals were simply kept out of the loop. No local is going to shoulder aside the “premier security agency in the world”, a quote from a British security expert. They’d assume the SS had things covered. The SS have utterly destroyed their credibility. I hope those rats know that.