Injuries from violent crime throughout England and Wales have dropped sharply, according to research by Cardiff University.
The study found violence admissions to A&Es had fallen
The study examined the number of admissions into emergency units as a result of violence and assaults.
Figures were 20% lower in 2004 than five years ago.
Researchers believe one factor was that CCTV cameras in town and city centres brought earlier intervention by police.
The study was carried out in more than 30 hospitals by the university's violence research group.
It found that across Wales and England as a whole the number of people admitted to casualty units because of violent crime was down by 25,700 last year, compared to the year 2000.
In Wales, the percentage drop in admissions was even higher, at 20%.
Professor Jonathan Shepherd, a professor of oral and maxillofacial surgery, who led the research, said there had been a clear and substantial decrease in injuries which he said was a "tribute" to police.
He told BBC Wales: "As people who treat the injured, this is really good news.
CCTV cameras allow police to intervene early, says Prof Shepherd
"We know that, according to this information, (the level of) violence stayed stable, and it was really good to see this converted into a reduction in violent crime in the subsequent five years.
"It seems to us that this is really a tribute to the police.
"One of the important reasons for saying that is that CCTV in town and city centres seems to act to allow the police to find out about more violence and then to intervene early.
"It's much like a teacher in a school playground, if the police get to an argument early, then okay, an incident has still happened but harm and serious harm have been prevented."
"I think this reduction really reflects the joined-up, integrated, approach with the councils, the police and NHS all working together to make sure we do intervene early."
The report also said that police statistics over the last 10 years have given an unreliable picture of violence because they list reported crime, rather than what is subsequently confirmed as a crime.
It stated: "Thus, far from representing a cause of concern, increases in violence recorded by police often signal decreases in serious violence."
Researchers collected data from a representative sample of 32 hospital A&E departments.
The report concluded there were "significant overall decreases" in serious violence across all age groups and genders.
The previous study was carried out between 1995 and 2000.