One relevant section from the apology/explanation letter: "The issues around the downloading of IIOC [indecent images of children] are that statistically out of a cohort of offenders, the predominant characteristic is that the offence will be committed in the main by white males. Only a very small percentage will be black, around 3%, and only around 2% will be female. Consequently, any arrests that are made for this offence will revolve around the male in the address as the starting point for the investigation."
Notably Rawls (the man indefinitely jailed) is black.
[1] https://www.buzzfeed.com/matthewchampion/this-mans-life-was-...