Eritrean child rapist allowed to stay in UK...

In answer to your question, I would of thought it was patently obvious. 

Foreign criminals, murderers, child rapists, terrorists, illegal immigrants, call them what you will, are very aware that their biggest challenge is getting to the EU. Once in the EU, thanks to open borders and freedom of movement it's plain sailing to Calais where under the nose of the incompetent EU and French authorities they pay people smugglers for a place in a cross channel dingy.

After disposing of all identifying documents (Because they're criminals and illegals) they're picked up by Border Farce cutters and treated like honoured guests, this is where they suddenly become 'refugees'. They are transported to luxury hotels (Illegals hotel bill is currently costing UK tax payers £15 million a day) where left wing charities coach them what to say to ensure they're never deported, then they're quietly pushed to front of some housing queue and given lots of lovely benefits.

If along the way 30 year old Abdul, who claims to be 15 years old, decides to rape a child, no worries. Left wing lawyers, again paid for by UK tax payers, will use human rights legislation that is specifically designed to protect foreign criminals and stop them being deported.  

Here to help.