The former police officer who shot dead Australian life coach Justine Ruszczyk Damond in an alley has received a 12.5-year prison sentence.

Lawyers for Mohamed Noor had asked for a one-year and one-day sentence after he was convicted by a Minneapolis jury of murder and manslaughter in April.

But Judge Quantance showed little mercy, announcing the 12.5-year sentence at the end of an emotionally-charged hearing.

Judge Quantance’s term matched the guideline sentence and the term proposed by prosecutors.

As Noor’s supporters protested outside, the fallen officer spoke to Ms Ruszczyk Damond’s American fiance and Australian family.

Noor, who admitted he took the life of “a perfect person”, said he had wanted to meet and talk to Mr Damond and Ms Ruszczyk Damond’s family members but was unable to because of the “cruel” court process.

He issued an apology and told how he wrote the family a letter from jail.

“I have wanted to sit with Mr Damond and tell him about what happened and to extend my condolences to him for the last two years as well as to Ms Ruszczyk’s other families,” Noor said in a voice that trembled with emotion.

“The process of the courts and the lawyers (are) so cruel in the way it makes us behave to each other.

“The system is de-humanising.”

Justine Damond’s family spoke of their heartache at the sentencing of her killer Mohamed Noor.

The public gallery was filled with tears as a video of her life was played.

Tears also flowed when Mr Damond, who was set to marry his “soul mate” in a romantic ceremony in Hawaii just weeks after the tragedy, delivered his impact statement to the court.

It was in the form of a letter he wrote to Ms Ruszczyk Damond.

Mr Damond’s heart-wrenching words included how they were planning to have a baby.

“I miss you every day – every moment,” Mr Damond said.

“I’m not sure how such a thing could happen to you, to us.”

Ms Ruszczyk Damond’s Australian family members were not in court but their impact statements were read.

Her father requested the maximum sentence and described how “Justine’s death has left me incomplete”.

“It’s like I lost a limb,” Mr Ruszczyk wrote.

Minneapolis has a large Somali expat community and protests erupted outside court after the sentencing, with Noor supporters claiming he was treated differently to white officers who shot minority members of the public.

Somali-American supporters rally for former Minneapolis police officer Mohamed Noor as he is sentenced for the murder of Australian Justine Ruszczyk Damond. Photo: Getty

Noor’s supporters held placards including “Black Muslim Immigrant Guilty” and “Noor: Victim of Identity Politics.”

Noor will have to serve two-thirds of the sentence before he is eligible for parole, although he is expected to lodge an appeal to the conviction and sentence.

Ms Damond, 40, formerly from Sydney’s northern beaches, called 911 to report a possible rape in an alley behind her Minneapolis home just before midnight on July 15, 2017.

When she approached Noor’s police squad vehicle he shot across his partner in the front seat and out the driver’s side window, hitting Ms Damond, who was in a pink t-shirt and pyjama pants, in the stomach.

Noor claimed he was startled and made a split-second decision.

Ms Damond’s family filed a $US50 million ($72 million) civil lawsuit against Minneapolis and the city agreed, just days after Noor’s guilty verdict, to pay $US20 million ($28 million).

-AAP