He could have been a Basil Thomson man. He was Irish. Note an armed guard was put on the hospital. A bit similar to John Ryan's death . His inquest is not available
He served in Irish Guards and RAF, note Mother's address on RAF service record and the same address on his Death Cert. I do not see how he got from Irish Guards to RAF. Also he has a 40% disability pension for GSW to arm, but I can find no entries in caualties
Note that he was working as a clerk in RASC in Royal Barracks
I suspect that this may not have been his real name as I cannot get him in censuses, nor a birth. The RAF record is certainly real. It looks as if he was born William Edward Allister Fraser. But even then there is no sign of his parents in 1901 nor 1911 censuses
Charles McQuaile (IRA) verifies a story that Michael Collins replaced the regular courier to enter the Castle and deliver a packet of mail from the Rotunda postal sorting office. This action confirmed that security inside the Castle was lax and secret correspondence lay about so that cleaners had access to it. McQuaile obtained a list of informers that named Fraser (Leslie Frazier) of Arbour Hill and Fitzgerald of Capel Street both shot and their bodies found. On 22 May 1921 IRA shot Leslie Frasier alias Frazer of 9 Blackhall Parade at a pub at the junction of Stoneybatter and North Brunswick Street. He died next day at the Richmond hospital but was able to tell the British about his attackers. His wife (? I do not think he married) claimed £4,500 at the compensation commission.
Dead of the Irish Revolution reports that IRA used 6 rounds of .45 ammo.
1895 Mar 10 Born Dublin is certainly him from RAF record, but the family are not in 1901 nor 1911 censuses. His RAF file gives mother as Kathleen. The BC gives born Ashtown, the RAF as Castleknock. This is the same place - Castleknock is part of Ashtown, Dublin
1913 Oct 18. In Mountjoy Jail. Convicted of stealing 5 copper boilers, value £5. Discharged on 27 Oct 1913 as first offence
1921 May 22. Shot in Dublin. Leslie W Fraser aged 24 employed as a Clerk to the Royal Army Service Corps at the Royal Barracks, Dublin attacked and mortally wounded leaving a pub in Stoneybatter. He was taken to Richmond Hospital where a Military Guard had been mounted. Lived in Blackhall Parade, Dublin. Served as 7140 Guardsman Leslie W Fraser, Irish Guards