On January 1st this year a taxi driver, Michael Atherton, shot dead his partner Susan McGoldrick.
He then killed her sister Alison Turnbull and Alison's daughter Tanya before finally turning the gun on himself.
Susan's daughter Laura managed to escape from the house wounded but alive.
It was later found that police had taken Atherton's gun licence after he'd threatened to harm himself. A report from the Independent Police Complaints Commission has also criticised the police for allowing him to get the guns back.
Now, the family say they need help from everyone in the region this Christmas so that the gun laws can be changed.
You can watch the full report from Frances Read below.
Sign the family's petition here.