yes there were armed and trained coppers just outside. so one needs to ask, why didn't they engage? it is their sworn duty to protect the innocent
which brings us to another distasteful episode of how this all occurred in the first place.
it seems that some time ago to make sure that the school got more govt money they did a deal with the local coppers and politicians to help get the crime rate down as a lot of the students were petty criminals. so they decided to reduce the number of arrests of the students so that the crime rate would appear to drop thus ensuring more money for the school - this was the second such agreement by a school in that area.
hence a possible reason for the inaction of the police at the scene and also a reason why the police and fbi did nothing even after visiting his house 39 times. so crimes were committed but the police did not charge the perpetrator nor did they keep the evidence of any crime. more here and much more detail - https://constitution.com/school-shooting-plot-exposed-wont-believe-set/
was this the sole cause? - probably not but could indicate the reasons for the inaction of the law enforcement bodies -
extract -
With the intricate nature of the relationship between the police and the schools, it became vital that the School Resource Officers (SROs) placed at the schools understood how the symbiotic relationship between the district and the police was supposed to work. They needed SROs who were adept at ensuring the criminal activities of their students would not be reported as crimes and endanger the district’s political and financial fortunes. This is likely why the much-demonized SRO Scot Petersen (who infamously stood outside of the school while the massacre was in progress), likely refused to share information on the shooter with social services back in 2016.
The sheriff’s deputy who did “nothing” while Nikolas Cruz killed seventeen people also refused to share information on Cruz with state social services during a 2016 investigation into his home life. http://wapo.st/2okxcVX
