The well-known Dungloe man was found beaten to death seven years ago following a brutal attack at his home in Meenacross.
As well as being attacked, Mr Duffy was shot with a crossbow by his attacker.
Despite an extensive Garda investigation, nobody has ever been arrested in connection with the brutal murder.
Mr Duffy’s family gather at 10am this morning at Meenacross to remember their brother and son.
They say they have received no update on Shaun’s death since his inquest more than a year and a half ago.
The dead man’s cousin, Fr John Joe Duffy, previously appealed to parishioners to help find Shaun’s killers.