Gardaí are continuing to question the man after Mr Murphy (27) died in the incident at a house in Carrigaline, Co Cork.
Gardaí said they were called to the scene of a serious assault in Sea View Avenue, at approximately 3.30am, where a man aged 27, was discovered with serious stab wounds.
He was later pronounced dead at the scene.
His body was removed to Cork University Hospital where a post-mortem examination was carried out, however, the results are not being released for operational reasons.
A second man, aged in his 70s, attended Cork University Hospital with serious stab wounds where he still remains.
His injuries are described as serious but non-life threatening.
Shane formerly played with Raffen Creek Pitch and Putt club and more recently with Rocklodge.
One neighbour said yesterday: “Shane was a lovely young lad.
“He was born and raised here … the whole family was.
“He always said hello and was so mannerly.
“Every Saturday morning, you’d see him sitting with his clubs on that wall there at the edge of the estate waiting to be picked up to go out playing for the day.”
Gardai said the 42-year-old man, "arrested in relation to this incident, remains detained under the provisions of Section 4 of the Criminal Justice Act 1984,” gardai said.
Gardaí are continuing to appeal to any persons who were in the areas of Carrigaline and Passage West in the early hours of this morning, who may have noticed any activity which caught their attention or can assist in their enquiries, to contact them at Togher Garda station on 021 4947120, the Garda Confidential Line 1800 666 111 or any Garda Station.