The Police Gazette has a long history, dating as far back as 1772 and taking various aliases. Most famously named Hue and Cry, its purpose was relatively self-explanatory: to advertise for wanted criminals across the UK police forces to enable them to catch, convict, and bring crooks to justice.
With the 1921 Census being delayed until June of that year, the Police Gazette records wanted criminals on either side of the census date, meaning perhaps that some of its wanted criminals can be found within the returns of the census, perhaps under a different name.