The father of a toddler murdered in the Christchurch terror attack – the youngest victim to die – has faced his son's killer and told him he could never be forgiven.

On the third day of the unprecedented sentencing hearing at the High Court in Christchurch, another 28 victims and family members are giving harrowing accounts of how the shootings have affected their lives.

Australian national Brenton Harrison Tarrant, 29, initially pleaded not guilty but later admitted 51 charges of murder, 40 counts of attempted murder and one of engaging in a terrorist act laid under the Terrorism Suppression Act 2002. He will be sentenced to life in prison.

Mucaad Aden Ibrahim, 3, was killed in the main prayer room at Al Noor Mosque as he clung to the leg of his father Aden Dirye.

"The defendant aimed directly at Mucaad and shot him with two precisely aimed shots," the summary of facts revealed this week.

Mucaad was born in New Zealand to a Somali family who fled fighting in 1995.

His father Aden Dirye told the court how he's been proud to watch his children grow up and be educated in his adopted homeland.

"The horrendous crime this evil man committed has shattered our lives. However we still love and feel we belong in this country," he said.

"This terrorist killed my beloved 3-year-old son. To me it is as though you have killed the whole of New Zealand."

Mucaad Ibrahim, 3, was the youngest to die during the attacks. Photo / Supplied

Dirye spoke of his little boy, well-loved in the mosque community where he used to distribute copies of the Quran, making friends with worshippers young and old.

"He used to engage and play with the police at the mosque," he said.

"At home, he would run around the house pretending to be a cop and wear a police uniform. We thought one day he might become a police officer.

"At home, Mucaad was the happiness of the household."

Dirye then turned to the gunman.

"Your atrocity and hatred did not turn out how you expected. Instead, it brought our peaceful community together," Dirye said.

"Know that true justice is waiting for you in the next life, and that will be far more severe. I will never forgive you for what you have done."

Mucaad's older sister Luul Ibrahim said Tarrant was "not worth the energy".

"Heartless, and worse than a rock," she said in a statement read to the court.

"[Prime Minister] Jacinda Ardern said you are unnamed, a nobody. You have united our community and country – you have united the whole world in solidarity with the Muslim community."

Another sister Khadra Ibrahim, who lived in Western Australia, was looking forward to meeting Mucaad in person for the first time.

Three weeks before she was due to fly across the Tasman, he was murdered.

"When I first heard the news I felt very numb, I was shaking," she said.

"Straight away I had a flashback to my video call with Mucaad where I promised I would come and meet him soon."

She said another sister was "destroyed" by the death.

Khadra made it to New Zealand after two weeks to support her family who were "struggling".

"I stood more than three hours in front of my brother's grave, talking, praying, crying," she said.

She had anger and hate towards Tarrant but she was trying to turn those feelings into something positive.

Mucaad was "incredibly special" and close to her heart – but she forgave Tarrant.

Abdelfattah Qasem died during the attacks. Photo / Supplied

Abdelfattah Qasem, 60, was shot in the head during the Al Noor rampage, and died a hero, his schoolteacher daughter Sara Qasem said today.

Sara Qasem demanded that the killer knew her father's name, repeatedly saying his name, Abdelfattah Qasem, and challenged him to pay attention.

In an emotionally charged, heartbreaking victim impact statement, the court heard how the slaying of Qasem, an IT specialist originally from Palestine and who studied in Canada and the United States, had devastated his family.

Sara remembered a "shining, glimmering man" with a hearty, ready laugh; a sweet, devoted father who never missed a Friday prayer.

"My Dad added value to this nation. I want to hear his voice. I want to hear my Dad's voice – my Baba's voice."

When the shooting started, and he realised he survived the first attack, Qasem stayed to help his brothers.

He died a martyr, his daughter Sara said, "putting others before himself" as he always did.

"This should not have happened. You made a choice here. A conscious, stupid, irresponsible, cold-blooded, selfish, disgusting, heinous, evil choice."

Tarrant blinked rapidly as Sara Qasem didn't hold back.

"I am uncertain there will be enough justice for what has happened at the hands of a terrorist – that's you," she said.

"However, I know one thing for sure - this monster who murdered my father, and the other beautiful souls that day in March, is a coward. That would be a familiar term to you. Those that fight with guns – cowards. You know you're not strong. You know you're weak. Look at yourself."

She urged the terrorist to take a look around the courtroom and ask himself: "Who exactly is the other here, right now? Is it us? Or is it you? I think the answer's pretty clear."

Her sister Rawan Qasem was living in Melbourne and was seven months' pregnant with Abdelfattah Qasem's first grandchild when he was murdered.

She spoke with her father the night before the attacks and he'd been so excited, having booked his flights to see his grandchild after he was born.

"He was robbed of his meeting his grandchild the very next day," she said.

"After the first round of shooting, he got up to say he was not hurt but could help others. He died helping others – a true reflection of his noble character."

Today, she sees glimpses of her father in her son, and urged Justice Cameron Mander to sentence Tarrant to life in prison without parole so "this terrorist does not get to see the light of day" and to protect future generations from harm.

Rahimi Ahmad was severely wounded in last year's attacks. Photo / Supplied

Rahimi Bin Ahmad, a 40-year-old service technician shot and badly wounded at Al Noor, was led into the courtroom in a wheelchair. He was at Friday prayer with his 10-year-old son when the shooting began.

"I was shot through my right side and lower back below my stomach. The shrapnel scattered throughout my lower back," he said in a statement, which was read to the court.

"I spent seven days unconscious in ICU and when I woke up I was paralysed. I wondered if I would ever walk again and at one time I thought they might need to amputate my right leg.

"I can remember every single moment of the shooting. It was nearly three months until I was able to come home."

He underwent multiple surgeries to wash out the bullet fragments – but that would spread them more and make his pain worse.

"They had to stop," he said.

He felt stressed, helpless and angry at his situation.

"I felt that I had lost control about my future and my ability to look after my family," he said.

"I can now sleep a maximum of four hours a night but it is common for me to go without sleep a couple of nights a week due to the pain of my injuries.

"This leaves me heavily fatigued. I can't live a normal life."

It took him a month to learn to walk again. He can now walk with the aid of crutches.

"Most likely I will continue to have spinal pain the rest of my life," he said.

Bin Ahmad worried about the impact the shooting had on his son who cannot be named for legal reasons.

"I feel guilty that I brought my son to the mosque that day and I blame myself for him experiencing what happened," he said.

"I worry for my son's soul – he has nightmares now and wasn't able to sleep at night for about four months after the shooting.

"The flashbacks of seeing me shot and others dying around me… it makes me cry thinking about it."

He said his son was anxious and jumped at loud sounds, making him worry how the massacre would affect his son for the rest of his life.

"He has lost his innocence and trust of living safely in New Zealand."

Bin Ahmad's wife Nor Abd Wahib then spoke directly to Tarrant.

"Look what you have done to my husband and my family. You already lost this battle from the moment you thought of harming us – even the last drop of your soul.

"But our souls are alive."

The sentencing hearing continues this afternoon.

- text by Anna Leask and Kurt Bayer, NZ Herald