I would have suggested going to the police

 

Problem with this is 'no drug use at work' doesnt mean they cant have one in the car when they arrive at work.  Not to mention the problems which may arise if one has an accident while under the influence, and the company knew about the drug use.

 

I realise he had to keep the family safe

 

You have as many weapons as u need - youd have the whole of NZ behind you