Given the number of corrupt cops already patroling the streets, I’m sure there will be roving gangs of them out to take what they can and gain control over people and entire neighborhoods.
In a post SHTF world we must be prepared for this. The first step in doing so is understanding that their position of authority ended with the structure collapse. When TSHTF, I’m not going to open my door to somone just because they’re wearing a uniform, Marauders can be wearing anything and come in the name of whoever they want. At that point, the playing field will be leveled.