Convicted criminals should certainly "live in prison". I don't think its fair to say that "these people" should be made to live in prison, delboy.
If the father is dealing drugs that's illegal and he is a criminal and he should be brought to justice and he should be accommodated in a fine prison cell instead of a nice housing estate with lovely neighbours.
I don't think one can, or should, dictate who their neighbours are but one can choose where they themselves live.
I couldn't agree more with Emma's comment above. Similar to Emma, I also bought a house in a "less affluent" part of Dublin recently but I am originally from the rural west of Ireland. I am very happy with where I live and my neighbours are fine in spite of the reputation attached to the area and to some of my neighbours.
Maybe my upbringing has instilled a certain naivety within me, and admittedly if I had a family I might look differently on the OP's plight. Or maybe my upbringing has resulted in me having a level of humility which gives people the benefit of the doubt.
As has been suggested, the OP could try and speak to the landlord to make his concerns known and this could lead to the outcome that he wants i.e the landlord might very well block this family from moving in to the house.
Jim I'm pretty sure yes if you had young children and were in my boat you'd be singing quite a different tune. Also just to be clear I had plenty of humility instilled in me growing up, also in the west of Ireland. But I also had plenty of other values and certainly one of those would be you work hard for an honest living and pay your way like my Dad did and I'm now doing. It wasn't to "give the benefit of the doubt" to a known drug dealer just because he needs a larger free house.
We only have 2 children because frankly that's all we can afford as we have to pay for everything, yet a family the other side of the village where neither parent works will soon have 4 children and because of the hand-out culture in this country they might well get an 1800 sq ft detached 4 bed house to live in and continue to deal drugs from and bring issues into our up until now quiet corner? You think we should be giving them the benefit of the doubt somehow just because he's not in jail?