How many stop and searches are knife crime related?

This claim is actually just referring to London. In the first three months of 2018, about 9% of stop and searches resulting in a “positive outcome” were for “weapons, points and blades. That’s according to Metropolitan Police figures (which excludes the City of London).

A positive outcome is where action is taken against people who’ve been stopped and searched, like arrests or warnings. The Met Police told us that “weapons, points and blades” included all offensive weapons except firearms, but including things like acid.  

By comparison, 60% of stop and searches with a positive outcome were drug-related.

We don’t have the same figures for England and Wales, but we do know that around 14% of searches that result in arrest involve offensive weapons, not including firearms. Just over half are for drugs. Given that these figures are only for arrests, we might expect weapons to account for a greater proportion of cases than in the London figures.

But if you want to find out how effective stop and search is at rooting out weapons, it’s more useful to compare the total number of searches for weapons and the number of positive outcomes.

In the first three months of this year, there were 5577 searches for weapons, points and blades, and 887 positive outcomes, which will include searches for other things (e.g. drugs) that happen to unearth a weapon.

The latest data for England and Wales covers from April 2016 to March 2017 when there were nearly 33,000 searches for offensive weapons, and about 7,000 arrests (arrests being only one of the positive outcomes). These arrests may also come about from searches for other things.  

The England and Wales figures relate to stop and searches made under section 1 of the Police and Criminal Evidence Act 1984 which makes up 99.8% of all stop and searches.