Denis Buckley was a son of Cornelius Buckley and Mary Coakley of Rathduane, Millstreet
Elizabeth Geoghegan was a daughter of Patrick Geoghegan

Denis Buckley, D.M.P. of Ladd Lane and Elizabeth Geoghegan of 13 Ashworth Place married on 20 October 1920 in the Church of Our Lady Immaculate, Refuge of Sinners, Rathmines.  The marriage witnesses were John Ryder and Mary Geoghegan.

Extract from Marriage Record

Death:

On this Find A Grave link we read:

Inspector Denis Buckley,
The Dublin Metropolitan Police and An Garda Siochana

Birth
son of Cornelius Buckley and Mary Buckley, formerly Coakley, of Rathduane, Millstreet brother of Mary C. Buckley

Marriage
Denis Buckley, a bachelor, Dublin Metropolitan Police, son of Cornelius Buckley, a Farmer, married Elizabeth Geoghegan, a spinster, from 13 Ashworth Place, daughter of Patrick Geoghegan, a Police Pensioner, on 20 October 1920, at the Church of Our Lady Immaculate, Refuge of Sinners, Rathmines.
The witnesses were
John Ryan,
Mary Geoghegan

Death.
Denis Buckley, aged 62, married, a Garda Inspector (retired), died on 9 July 1953, at 67 Lower Beechwood Avenue, Ranelagh.
The cause of death was Myocarditis, 6 months, Cardiac Failure, certified. His death was registered on 16 July 1953, by Marion E. Buckley, daughter, 67 Lower Beechwood Avenue.

His name is not recorded on the headstone
 

Obituary

The inscription on the headstone reads:

    +

in loving memory of
ELIZABETH BUCKLEY
died 14th January 1976
MARION BUCKLEY
died 19th December 1981
SHEILA BUCKLEY
died 23rd December 1983

rest in peace

On Find A Grave we read:

Marion C. Buckley

Mary Buckley, daughter of Cornelius Buckley and Mary Buckley, formerly Coakley, of Rathduane, Millstreet, Co. Cork

Sister of
Denis Buckley

aged 83,
late of 67 Lower Beechwood Avenue, Ranelagh
 

Burial:
Deansgrange Cemetery, Deans Grange, County Dublin
PLOT St. Ita, X 12