OP has probably been reading the Derby Telegraph or BBC Derby, rather than the Daily Mail.
It was a shocking, senseless crime. The offender chose his victim randomly from sitting across the road, walked into the bank, stuck his knife into his victim, and walked out. He was in the bank for 22 seconds. That 22 seconds stole a life; a family man, a business owner, a well regarded member of the local community.
Broad daylight, middle of a busy day.
(Followed up a few weeks later by a gang of masked youths smashing their way through the jeweller's window directly opposite- naturally no one tried to stop them because of the very high risk of violence)
Derby like many other Midland/ Northern cities and towns has its social and economic problems. Its capacity to deal with people of violent, (traumatised?) disposition who have engaged with criminal networks to travel across Europe is very limited. Significant proportions of the local population are already struggling and have been for many years.
Derby's problems are complex and not down to any specific demographic, but a constant trickle of incoming people with complex problems and extremely limited support does no one any favours. Derby is hardly unique either.
I really don't know what the answer is because we live in an interconnected world where people can keep trying and moving around, but we are stuck in a politically messy situation where it's difficult to establish peoples' origins, motivations and needs, and there are a number of dangerous people who exploit that to the detriment of the rest of society.