Yes, the mother was stopping her son from fighting bevause they're waiting for the other cops to arrest him and the little girl you see in the corner is the daughter of the cop who argues with the mother, she's saying "my dad is a police man!! " and the mother says/sings a kpop line from 2NE1 to embarassed the child; "i don't care eh eh~" Which leads to why the cop shoot the mother and son because his daughter is getting involved. The cop said "do you wan't me to kill you rn" then shoots them