From CWGC

Rank: Corporal
Service No: 12242
Date of Death: 03/06/1916
Age: 33
Regiment/Service: Royal Engineers “B” Coy.
Awards: D C M
Grave Reference: 9. 21.
Cemetery: MITCHAM (CHURCH ROAD) BURIAL GROUND
Additional Information: Son of Mr. J. H. and Mrs. C. Brett, of 2, Alpha Terrace, Nursery Rd., Mitcham.

1900 Electoral register shows James Herbert Brett in Nursery Road.

His name is on the south face of the Mitcham War Memorial

See list of WW1 graves in the Parish Church.

Awarded the Distinguished Conduct Medal, as reported in the London Gazette 30th June 1915.

12242 Sapper W.H. Brett, 9th Fld. Co., R.E. (LG 30 June 1915). For conspicuous gallantry on the 9th April, 1915, at Givenchy, when, engaged in erecting wire entanglements in front of the trenches, after dark, he assisted in rescuing, under a heavy fire, one of the covering party who had been wounded.

Source: Ancestry.com. UK, Citations of the Distinguished Conduct Medal, 1914-1920 [database on-line]. Provo, UT, USA: Ancestry.com Operations, Inc., 2010.
Original data: Walker, R. W., and Chris Buckland, compilers. Citations of the Distinguished Conduct Medal, 1914–1920. 4 sections. Uckfield, East Sussex, United Kingdom: Naval and Military Press, 2007.