The latest incident saw paint thrown on the memorial on White Brae on Sunday afternoon.
Stewart Dickson MLA said: “I am absolutely horrified that this memorial has yet again come under attack and I would call on all political parties to condemn this latest incident.
“This despicable act of desecration is nothing short of a hate crime and will have caused further pain to the families of the three victims.
“I am calling on those with responsibility and influence in the White Brae area to demonstrate community leadership and help to track down those responsible.
“I would also urge anyone with information to contact the PSNI as soon as possible.”