US President Donald Trump has repeatedly attacked London Mayor Sadiq Khan over knife crime in the British capital, most recently calling him “a disaster” only days after visiting. The president tweeted that Khan was a “national disgrace” after two teenagers were killed within ten minutes of each other last weekend. But how does London compare to US cities, and is Trump right to criticise? What data is available to put the president’s remarks into context? Trump has made his remarks about knife crime while defending America’s gun laws despite mass shootings. He appeared as a guest at the NRA annual convention in 2018 and spoke about London’s tight controls on gun ownership. “That’s right, they don’t have guns, they have knives,” Trump said, telling his audience of blood-soaked hospital wards. “Knives, knives, knives,” he said, making a stabbing motion. His most recent outburst came with a retweet of a notorious right-wing commentator who previously branded migrants “cockroaches” and who described the British capital as “Stab-City” and “Khan’s Londonistan”. But while official statistics show a clear increase in knife crime in London, they also confirm that the murder rate is well below most US cities. And despite the recent uptick in fatal stabbings, which Khan last week described as “sickening”, London’s knife murder rate is lower than in Trump’s hometown city, New York. From multiple agencies, including annual census data and population projections, it is possible to obtain a comparable figure for crimes per 100,000 people. The FBI compiles murder data from across America, while the Office for National Statistics in England and Wales and the Scottish Government compile similar numbers for Britain. But while the US figures can be broken down by state or administrative region, they do not always correspondent exactly to urban boundaries and the FBI notes that some counties do not report all the information. British figures are also not directly comparable as they are sorted by financial year instead of calendar year as in the US The most recent geographical FBI data is from 2017, while individual police forces have figures as recent as early 2019. New York Police Department keeps a searchable database of murders by category. London’s Metropolitan Police also provides data on knife crime and murders but does not provide a specific tally of knife-murders. Instead, third parties such as website Murdermap collate numbers based on individual deaths. Other potential flaws in comparisons include annual fluctuations caused by major terror attacks and geographical anomalies. In New York, the wider metropolitan area is larger bigger than the five boroughs covered by the NYPD — although the city’s official population is very similar to London’s. In London, Metropolitan Police crime data also excludes the City of London, the small historical administration of the mostly financial district which has its own police force. Fact-check and investigation outlet Bellingcat provides a more detailed analysis of the available sources. The FBI notesthat rankings of crime by city and county “provide no insight into the numerous variables” affecting local crime and lead to “simplistic and/or incomplete analyses that often create misleading perceptions adversely affecting communities and their residents.” Since aggregated murder data also includes non-negligent manslaughter, homicide rates can also be affected year-to-year by court judgements and the rulings of public inquiries into disasters. There were 17,284 homicides in the US in 2017, giving a rate of 5.3 per 100,000. In Britain, there were 785 in financial year 2017/18 — the nearest equivalent time period — giving a rate of 1.8 per 100,000, some three times lower. Within this, there were 285 knife murders in England and Wales in 2017/18 — the highest number since the Second World War — and 34 in Scotland, giving a combined British rate of 0.48 per 100,000. In the US, the number for 2017 was 1,591, giving an almost identical rate of 0.49. So even amid a spike in British knife crime, Americans as a whole are at least as likely as to die from a stabbing. More recent police data is available for both cities, including a direct comparison for the calendar year 2018. The official estimated population of New York was 8,398,748 at July 1, 2018, and 9,006,352 for London. The NYPD murder total for the year was 295 — less than half the figure for 2001 and a fraction of 2,200 victims counted in 1990 — giving a rate of 3.5 per 100,000. In London, there were 136, giving a rate of 1.5, so New York remains twice as deadly despite a successful decades-long crime crackdown. Within this, there were 76 homicides attributed to cutting or stabbing in New York — the exact same number as in London, according to data from Murdermap. But New York’s rate is slightly higher, at 0.9 compared to 0.8 in London. It means the Big Apple is still deadlier for knife attacks, but the pattern of recent years suggests that could be reversed very soon.