I strongly suspect that it's harder to find suspects to charge who have fewer local links and less documentation. I also suspect the CPS is probably failing to bring cases in a level and fair way, why bother when the judge will let them off without jail time because of 'cultural differences'? [0][1]. We know that migrants are 350% more likely to be arrested for sexual crimes than British citizens [2], but that's only some of the picture and the government wont release full figures.

[0] https://www.dailymail.co.uk/news/article-2268395/Adil-Rashid...

[1] https://www.deccanherald.com/world/rapist-uk-spared-jail-bei...

[2] https://www.telegraph.co.uk/news/2025/01/05/foreign-national...