Ihaka Stokes was 14 months old when he was murdered by his de facto stepfather Troy Taylor.

The mother of Christchurch toddler Ihaka Stokes has spoken of losing "both her best friends" as her former partner was jailed for killing her son.

Mikala Stokes told the High Court in Christchurch she was left "broken" by Ihaka's death, just before her former partner, Troy Taylor, was sentenced to life imprisonment with a minimum non-parole period of 17 years for murdering the toddler.

Taylor was also sentenced to two years' jail for assaulting Ihaka the day before he died.

JOHN KIRK-ANDERSON/FAIRFAX NZ Troy Taylor showed little emotion as his life sentence was handed down.

He had pleaded not guilty at his trial in March and accused Stokes of harming her son on the afternoon of July 3, 2015, while he was out of the house.

READ MORE:

* Troy Taylor found guilty of murdering 14-month-old Ihaka Stokes

* Blood on the wall: How toddler murderer Troy Taylor tried to pretend he hadn't killed Ihaka Stokes

* Lead detective had 'terrible dreams' during Ihaka Stokes murder investigation

When he gave evidence in his own defence, he said he initially lied to police to protect the pregnant Stokes, telling them that Ihaka was hurt in an accidental fall in his cot.



In her victim-impact statement, Stokes said she had "never felt so alone" since Ihaka's death and Taylor's arrest.



"In two weeks I lost both my best friends."



Ihaka was rushed to Christchurch Hospital with serious head injuries on the night of July 3, 2015, but died shortly after.

FAIRFAX NZ Mikala Stokes told the court she was left "broken" by Ihaka's death and Taylor's arrest for murder.

He was later found to have suffered 59 separate injuries. Autopsy scans identified a number of broken bones, including both shoulder blades, his left forearm and several vertebrae.

The prosecution and defence agreed Ihaka's injuries were "non-accidental".



Stokes recounted the trauma of rushing to hospital that night and the subsequent police investigation.

"When we arrived at the hospital after being told what to do, no-one ever really told me what was happening. I went to say my final goodbyes [to Ihaka], but I never really go the chance.

JOHN KIRK-ANDERSON/FAIRFAX NZ Ihaka's grandfather Paul Stokes said he struggled "every day" to cope with the toddler's death.

"When I was being interviewed it was such an overwhelming experience. I was still trying to come to terms with the fact I would never hold my Ihaka again."

She likened the experience to a "science experiment".



"I trusted you, Troy," she said.



"I'm sorry, Ihaka, [that] you had to go through this."



Her father, Paul Stokes, said Taylor had been a "loving and supporting friend" to his daughter.



The death of his grandson had placed a "huge strain" on his marriage, he said. He struggled to sleep at night or put in a full day's work. He and his wife, Yvonne, argued over "the silliest things".



Stokes described a rainbow carving he had made for his rainbow-loving grandson since his death.

"If tears were stairs, I would build a staircase to heaven and bring you home."

FAIRFAX NZ Mikala Stokes and Troy Taylor together at Ihaka's funeral in 2015.

In sentencing, Justice Cameron Mander accepted that Taylor's offending was out of character and his sorrow at Ihaka's death genuine.

However, the toddler's vulnerability and the severity of his injuries were aggravating factors, the judge said, along with Taylor's attempts at exoneration by changing his story.

"In my view that demonstrates a certain callousness and a certain disregard for Ihaka's family and importantly an inability by you to face up to the enormity of your actions.



"The victim-impact statements … reveal the understandably profound and ongoing impact of the loss of Ihaka. There is nothing I can say which can better communicate to you the deep grief Ihaka's family have suffered."

In sentencing arguments, Crown prosecutor Mark Zarifeh said Ihaka's injuries, suffered over two nights, put Taylor's offending at the serious end of the scale, even though his attacks were a "momentary loss of temper".

"That, unfortunately, is the case in a lot of these kinds of cases; these kind of killers. Often there can be no previous offences . . . and not usually any allegation of intentional killing or planning of any sort."

Defence counsel Phil Shamy said his client maintained his innocence. Shamy agreed the assault was "out of character", and urged the judge to impose a shorter non-parole period.

"[There is] certainly no doubt [Taylor] adored Ihaka and he adored Ihaka's mother. This whole offending can be regarded as aberrent."

Taylor said little at the hearing, his eyes downcast as the victim-impact statements were read. As he was taken down, he acknowledged his parents and other family members in court.

"Thanks for coming," he said.