Andrew Allen who was originally from Derry, was shot dead at his home at Links View, Buncrana in February.
The vigilante group Republican Action Against Drugs later said it carried out the murder.
The dead man’s sister Michelle said the support of the community in Top of the Hill was a big comfort to the family.
Nobody has yet been arrested in connection wit the murder.
Gardai recently appeared on RTE’s CrimeCall appealing for the public’s help in their investigation.