The unveiling of a National Police Memorial follows a 10-year campaign by the Police Memorial Trust, set up in the wake of the shooting of WPc Yvonne Fletcher in 1984. Twenty-one years on, one police officer tells how the job has changed.
Pc Norman Brennan joined the force 27 years ago
Pc Norman Brennan, who serves with the Met Police, says the main difference between policing 20 years ago and now is simply that the UK is "a far more dangerous place".
"The streets of Great Britain are the most dangerous that we've policed since World War II," he told the BBC News website.
"The British police are predominantly unarmed and are facing armed terrorists, armed crack dealers and armed robbers.
"They are also facing people that carry knives and are prepared to use them against anyone that stands in their way."
Anyone who attended Tuesday morning's memorial unveiling would be "all too aware" of the dangers of modern policing, he added.
The change in the nature of danger had inevitably led to different equipment being used, he said.
"The batons are a bit longer, we have CS spray, and the handcuffs are more up-to-date."
But the mentality required for the job offered an even more marked difference.
"We now have to have the attitude of a soldier going into combat on a day-to-day basis," he said.
Pc Brennan, who is also director of the Victims of Crime Trust, said a feeling of solidarity with other members of the force had changed.
The memorial to officers who have died on duty was unveiled on Tuesday
"When I joined the force 27 years ago there was definitely more of a sense of comradeship.
"It was almost like family - all looking out for one another.
"But now we have a lot of targets, it's a different job."
The stressful nature of the job meant a sense of togetherness had been lost, he said.
"It's a very much more lonely occupation than it was in the past."
In the last 20 years danger has gone right up and morale has gone right down
But the change in mentality was largely down to the increased danger.
"When I joined the service in 1978, there were a handful of firearms offences each week," he said.
"Now there are 423 a week on the streets of Britain.
"In the past 20 years danger has gone right up and morale has gone right down."