It's been ""known"" for years that Special Branch helped murder people in Northern Ireland, and outside the republican community and the small subset of mainland "left" that pays attention, it makes no difference.
https://www.belfasttelegraph.co.uk/opinion/news-analysis/how...
(Far too many of the "british people" read rightwing press outlets which will minimise this and some other issue, probably Brexit, to rile up their readers to demand more not less authoritarianism)