Drug Dealing = If you are dealing drugs (this is a form of role playing) if the police approach you or are heading your way then you may open fire... please be advised the police will shoot back if shots are fired.
"We're in a sports hatchback they are in an offroad, we can catch up"
To me that sounds like you were going to approach them or head their way.
However, without proof they were carrying drugs we cannot figure out whether this was within the rules or not. I will try and sort out a definitive rule surrounding this today, so unfortunately unless said proof is there I cannot make a judgement. If there is a screenshot/video of them either fleeing from the drug dealer/processor/field or their name on the wanted list with drug trafficking next to it, then I may be able to make a decision. However this means that you, the cops will have to post evidence which backs up the player you are reporting, so I hope I am not wasting my time in asking you to do the right thing, as we will all benefit.