Like the article says, the crowdfunder is for the family of the officer (as the officer is likely going to jail). French authorities would have immediately stopped a crowdfunder going directly to the officer, as that would be illegal per French law.

This is s tragedy all-in-all but what I would like to know: Nahel M. was 17, therefore driving illegally (no license), why was he doing this? Why didn't he stop at the checkpoint? Why try to drive away? Was it a stolen car (it had Polish plates)?

Sadly, had Nahel M. stopped and done what the police say, I believe Nahel M. would still be alive. They would have certainly arrested and charged him (reckless driving, no license, possibly stolen car, and so on). Perhaps Nahel M. was afraid of being arrested like this, possibly a justified fear based on his experiences in the banlieue.

However, his attempt to drive away suggests he was aware of his actions being illegal and he wanted to avoid the consequences. Why would one do something illegal in the first place, if one wants to avoid consequences with the police?