But people have been slow to accept this and the sickening increase in youth crime in recent weeks has damaged the reassurance message.
The Home Secretary says people are 'nervous and unconfident'.
Tackling knife crime sets a real test of the ability of police, councils and the health service to work together. It also poses a challenge for their comms teams to support law enforcement with co-ordinated PR that reassures the public and deters crime.
The detection of crime is a police matter. But local councils can take the lead in building relationships with young people and explaining what is being done to make the community safer.
And the local health service has a central role to play in spelling out the physical consequences of being stabbed.
Winning the PR part of this battle will require more use of young people as advocates. Politicians and senior police officers can set the context, but television inevitably exaggerates the negative issues and we need arguments and spokesmen that will be credible on Facebook, rather than Newsnight.
The single most effective piece of PR on this issue over the past week has been interviews with young convicts explaining why they knifed other youngsters. The typical reasons given were fear or panic.
By allowing these offenders to discuss the crime, regret for the victim, and the waste of their lives, the prison service provided a powerful argument for not carrying a knife.
The duty to develop a coherent reassurance strategy and campaigns that deter children from seeing violence as acceptable will remain after the news agenda has moved on.
A positive legacy from these individual tragedies would be more effective communications from the main public services, and that may save lives in the future.
Alex Aiken is director of comms at Westminster City Council