'12' has a parallel to Chicago, and December, the month this happened in.
The emphasis here is Christmas weekend. 12/25 = 12+25 = 37
Christmas also has a connection to 'death'.
45 guns were seized over the weekend! HA!
Remember, '45' is the sum of the magic square of Saturn, and Christmas is 'Saturnalia'.
96 homicide reports?
64 non-fatal shootings?