> I think the thing you said about priors is repeating a talking point about prosecution or sentencing disparities that isn't particularly relevant in the context of an arrest.
Arrests don’t occur in a vacuum. The prior convictions are known and are a factor.
> I have no idea what you mean about multiple charges.
Person A is smoking pot and is arrested. Person B is smoking pot wearing a bloody t shirt with a knife in his hand. If you’re more likely to engage in criminal activity, you’re more likely to be smoking pot while engaging in criminal activity (again, on average).