Two very interesting websites, looks like they are by the same guy, one on the so-called "Cairo Gang" of British intelligence officers killed by the IRA, the other on the Auxiliary Division Royal Irish Constabulary.
Two interesting things (out of many) that come out of these websites.
Firstly, there was not really such a thing as the "Cairo Gang". There was a group of officers referred to by the IRA as the "Special Gang" but these were all men in F Coy ADRIC and not amongst the men killed on 21 Nov 1920. Some of the men who were killed were intelligence officers, others were military prosecutors, others were just in the wrong place at the wrong time.
Secondly, the varied and interesting backgrounds (and in some cases futures) of the "Auxies". Almost all of them were ex-officers who had served in WW1 but very few were ex-regulars. Some had been commissioned on the basis of pre-war service in a school or university OTC. Others had served for a time in the ranks of an "officer-producing" unit such as the HAC or one of the public schools battalions before being commissioned. Probably the largest group had seen active (sometimes distinguished) service in the ranks before being commissioned in the field or being sent for training at an officer cadet unit. Some of this group were ex-regular NCOs but most were ex-TF or "hostilities only" men. A handful hadn't been in the army at all but were ex-RN/RNR/RNVR. A surprising number (to me at least) of those who had held army commissions were former RFC pilots or observers and some of these men rejoined the RAF after their ADRIC service. Others had seen distinctly non-combat service in units such as the Chinese Labour Corps. The majority had served as infantry or gunner officers.
A few men went back to the RAF or Army after their ADRIC service, a number as rankers since officer vacancies weren't available. Others went on to other colonial police forces, particularly in Palestine. Many emigrated from the UK to Canada, Australia etc. Some had very normal lives in the UK afterwards, it would seem many didn't.