The Police shooting of Charles De Menezes didn't set a precedent , because it was a one off that didn't happen again .
Brazilians getting deported and Brazilians getting killed by the UK Police are two very different things .
They have indeed been clampdowns on illegal people in the UK .
Read all about it here :
"The policy has been cited as one of the harshest immigration policies in the history of the United Kingdom, and has been widely criticised as inhumane, ineffective, and unlawful"
https://en.wikipedia.org/wiki/Home_Office_hostile_environment_policy