The same thing that causes every other crime spike both here and everywhere else in the developed world. Negros, but it's not really their fault. In the years before it was deemed politically incorrect, a ton of science was done on the subject and it shows the negro brain is very different to the caucasian brain in size and structure yet all the standards we call civilized behaviour were the behavioural norms of caucasians that made the laws based on them. Those standards were not then and are not now the behavioural norms of negros so how are they supposed to be expected to adhere to them as if they were?