I’ve seen cold, lifeless teenage bodies lying on the mortuary slab.
I’ve seen the grief and the long-lasting impact of serious and organised crime – and it is shocking.
But for what? It feels like for nothing. This is a completely senseless loss of life with no justification whatsoever.
The news from Tottenham last night, where a 17-year-old girl was gunned down, is the latest tragic case that shows London's murder rate is spiralling out of control.
As a former undercover cop and drugs officer with Scotland Yard from 1985 to 1999 and author of The Gangbuster, I’ve seen London and other major cities are really suffering from a proliferation of young people taking weapons out onto the street and using them.
I tackled crime gangs whose names you may have heard of, the Arifs, the Richardsons and The Adams family, but I also tackled many groups, gangs - call them what you will - that were far from household names, but no less ruthless.
With a gun or a knife in your hand you are scary, very scary and the weapon-carrying youths of today know it.
I've been stabbed in the neck, I've stared down the barrel of a gun a few times, each time by people who thought a weapon made them safer.
They could not have been more wrong. Once I was on their case they faced inevitable jail.
When gang faces gang, death is often the consequence.
A violence epidemic
For all the efforts of myself and my colleagues, it breaks my heart to report that there are more guns and knives on the streets today. The streets are awash with them.
But with 20,000 less officers on the streets, is it any surprise?
Knives are everyday items in every home in the country so they are very easy to get hold of.
If it’s the norm to carry a weapon, there will be a natural progression toward using it.
So many people are desensitised to the consequences of those acts.
So much of this problem of young people being slaughtered centres on the supply of illegal drugs.
There are very few other types of crime that gangs will specialise in.
Impossible to escape the poisonous culture
Fear is a powerful emotion and so many of these people reign by fear.
Young people are groomed for their activity - they know what is important to you, your family and your locations and they will use it to control you. They know their territory.
It’s a frankly terrifying scenario to be confronted with.
No one can leave. It’s a poisonous, ensnaring culture. And it has a further reach now as gangs send children across county lines, on the train, coach or car to find new markets within which to sell drugs.
The gangs of today do not enjoy the family name notoriety of people like the Krays, but they give themselves monikers that boast of their ability to earn cash, to extol violence upon their rivals and sometimes their disregard of women.
I am not going to massage their egos by naming them here. They need punishing not publicity.
Gang grooming
A young person without a strong sense of a family unit wants to belong somewhere. If they don’t come from a strong, cohesive family background, and someone who has a wad of money, the best phone and a car, they have found a leading light.
They want to emulate that person. It’s very easy for them to get drawn in. It’s easy for them to corrupt these young people into doing small errands at first - delivering drugs in exchange for some money - £30 or £40 at first.
All of a sudden, they’re doing it regularly and are owned by these people.
You are part of the gang and once you’re in, leaving is difficult - to the point of being impossible. They know where you live, where you hang out.
No one travels very far, people stick to their neighbourhoods.
The price of police cuts
Savage cuts to policing have happened in the last eight years and local policing has been sacrificed to divert resources elsewhere.
It’s no coincidence that the age of austerity has impacted enormously on the policing of today - there are 20,000 less police officers than eight years ago.
It’s a massive number. There are consequences.
You are deluding yourself if you make cut after cut after cut and expect there not to be consequences.
You reap what you sow and the age of austerity needs to be consigned to the dustbin of history and we need to re-prioritise.
There are enough people with billions out there to pay more money into public coffers.
When I was a young uniformed cop, youngsters lived in fear of turning a corner and bumping into me - because if they did they would be asked where are you going, where have you been, what are you doing, turn out your pockets.
We would strip search them essentially - we didn’t walk up and randomly search people. We went to where the crime hotspots were.
We went to the troublesome estates and to where reports of crime had come from.
We also relied heavily on what were then called 'home beat' officers, which are now called neighbourhood policing teams.
If things weren’t getting done and weren’t improving, it would be those home beat officers who were responsible and who would be upset if a crime was committed on their patch.
Punishment and education
I’m a big fan of preventative education in primary schools - my children were educated out of smoking at primary school.
We can do likewise with the carrying of weapons, the taking or dealing of drugs and the consequences of violence. Get them as early as you possibly can.
The number one tactic short-term is to increase police numbers.
I wouldn’t write off this generation but we need people at the gates of primary schools who are young and engaging, going in and pointing out the consequences.
In order to support that, we need increases in police numbers so that when a youngster walks onto the street, they have that nagging fear in the back of their minds that they might get stopped and searched by a police officer.
The consequences for carrying that weapon should be severe: punishment, education and a form of rehabilitation.
The punishment must fit the potential consequences of the crime, not necessarily the crime itself.
If you are found in possession a knife, you should be punished as a potential murderer.
Punishment without rehabilitation is absolutely pointless; sending a young person to prison for drug dealing without rehabilitation is a waste of time and money.
We want to show them what they are missing and what they might want to buy into.
We must give hope to people who have lived within gangs - hope that they can aspire to own a house of their own, a decent car on the driveway and job that will pay for that. They can pave a better way.
If we don’t, all we are creating is mincing machine, where we stick them in at one end and they come out worse the other.
Enough is enough
There is an obligation upon us and upon the government to start doing more. Enough is enough.
All these things take money. So often, the spineless senior police officers who have to deal with these budget cuts are too concerned about their precious post and the precious pension to say what they might say privately.
They put self before service.
Senior police officers across the country should have been in absolute uproar for the last eight years - saying this is wrong.
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But their voices have been noticeably absent because they risk losing that promotion or that pay rise.
It’s going to take a joined-up effort by a lot of people but we have to get young people to put down their weapons.
How much more teenage blood must be spilled before the Prime Minister stands up and says this is enough? It really has got that serious.