The father of three children killed by their mother said he was "pained to the core" that he could not protect them.
Pasquale Riggi's eight-year-old twins Austin and Gianluca and their sister Cecilia, five, were stabbed by their mother Theresa on 4 August 2010.
She has been jailed for 16 years after admitting culpable homicide on the grounds of diminished responsibility.
Mr Riggi said the "horrific manner" in which his children died would leave an "indelible mark" on his life.
In a statement, read on his behalf outside the court following Riggi's sentencing, he said: "The horrific manner in which my children died will leave an indelible mark on the rest of my life.
"As a father, my natural instincts were geared toward safeguarding my children from the dangers of this world.
"It pains me to the core that I was unable to protect them from the selfish, brutal and murderous acts that ended their lives so unfairly on August 4, 2010.
"There is no justification for this heinous crime, repeated three times.
"Nor is there any sentence that can provide justice for the overwhelming loss of three lives and the subsequent painful grief and devastation caused to surviving family and friends alike."
Mr Riggi was wearing three different coloured ribbons to represent each of his children - red for Luke, yellow for Austin and pink for Cecelia.
He said he would never forget his children, who left "lasting impressions" on him.
"I think about them at least 100 times each day," he said.
"They are in my thoughts when I wake in the morning and before I go to sleep at night.
"They were such wonderful, energetic, bright and happy children.
"Those of us who had the pleasure of knowing Cecilia, Luke and Austin looked forward to watching them grow while they independently navigated through their unique life journeys.
"We are so thankful for the opportunity we had to know and love them and for the memories that we made together, allowing us to cherish them so dearly now."
He added: "My family and I wish to thank all those who have provided, and continue to provide, tremendous support."