Sergeant William Thick

[The Grave Maurice]

The "Upright" thing most likely did refer to Thick's character. However, Walter Dew says in I Caught Crippen:

If the criminals were known to the detectives, the detectives were also known to the criminals. We were all given nicknames, some of them very apt. A sergeant named Thick, who was a holy terror to the local law-breakers, was known as "Johnny Upright", because he was very upright both in his walk and in his methods.

[Robert]

Chris, Thick appears in a Pall Mall Gazette article of Oct 29th 1891, which is too long to post in its entirety, but here's the start of it :

[ChrisGeorge]

Hi all

On the Wiki page on Segeant William Thick here on Jack the Ripper Wiki it is stated: "Thick was one of the more colourful members of the investigative team and widely known by the nickname 'Johnny Upright', although whether this referred to his character or posture is uncertain." It would seem to me more likely that, given that he was a person in a position of authority, that the "Upright" was a reflection on his character.

A statement in Jack London's People of the Abyss (Macmillan, 1903), on "Johnny Upright" (Chapter 2), although the author does not give his name outright, would seem to confirm that assessment. For London writes, "A detective of thirty-odd years' continuous service in the East End, known far and wide by a name given him by a convicted felon in the dock, he was just the man to find me an honest landlady, and make her rest easy concerning the strange comings and goings of which I might be guilty [as a writer researching the poor of the East End]." [Emphasis mine.]

Chris