Perhaps some context to complaints re #stopsearch in London: there has been a massive increase in volumes over the last 2yrs.

The result: falling arrest (and positive outcome) rates, down from 18.2% (30.7%) in Jul 18 to 9.1% (19.8%) in May 20. https://www.met.police.uk/sd/stats-and-data/met/stop-and-search-dashboard/

1/ THREAD https://twitter.com/gmhales/status/1278412091922223105

There is an inverse relationship between volumes and arrest/positive outcome rates. As volumes of #stopsearch increase, numbers of 'false positives' increase faster = more potential for complaints (all else being equal) and more risks to legitimacy.

2/

A key way the reduction in #stopsearch in London was achieved after 2011 was through a focus on the strength of grounds (how 'reasonable' were they) and arrest rates. A 20% arrest rate target was introduced and SS fell until it was reached. https://twitter.com/gmhales/status/955808728506359809?s=20

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Here's the relationship between volumes and arrest rates. #stopsearch fell until the 20% arrest rate was achieved (at around 10k stops/month). https://twitter.com/gmhales/status/887983769910751233?s=20

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Around 2 yrs ago, in the context of rising #knifecrime and homicide, the emphasis shifted away from grounds and arrest rates to increasing volumes (based on first hand accounts from serving officers). Last year a Commander said they were aiming for 30k/month.

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Worth saying the SS falls after 2011 had been driven first by pressure from @ehrc in the aftermath of the riots, but then (esp nationally) T May's reforms. The end of her period as Home Sec and then PM removed the political pressure to hold nos down. https://twitter.com/gmhales/status/971345867696427009?s=20

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A key tool in the Met #stopsearch increase has been the use of TSG - highly mobile specialist officers in vans providing support to boroughs/BOCUs across London (who 'bid' for them). Significantly, they are not policing communities they know well. Ditto VCTF & 'Blunt serials'

7/

I would speculate that the lack of local knowledge has implications in terms of how 'reasonable suspicions' are formed, likely relying less on specific info/intelligence about particular individuals, and more on behaviours and contexts.

A recipe for more false positives?

8/

Perhaps also worth saying that a concern raised by officers during the years of low rates of #stopsearch was that officers were getting 'de-skilled' and losing confidence to do SS well. Add to that an influx of inexperienced new recruits...

9/