The Joint Declaration was agreed upon at an informal meeting of the European Chiefs of Police in London hosted by the National Crime Agency on 18 April.
Police Chiefs of all EU Member States and Schengen Associated Countries were invited, alongside Europol’s Executive Director.
Here is the declaration (pdf).
If you make encryption illegal, only criminals will use encryption!
As far as I know killing people is illegal, hasn’t stopped some to do it nevertheless. And it won’t help protect the infamous “the children” either.