Louis De Zoysa has been given a whole-life sentence for the murder of Met Police Sgt Matiu Ratana - who he shot in a custody centre in September 2020
The judge told De Zoysa his autism was not blame for the killing: "You are to blame"
He also said police treated De Zoysa with dignity and respect, before the fatal attack
The sentence means the 26-year-old will never be released from prison
Though handcuffed, De Zoysa shot an antique gun that he'd smuggled into the centre in Croydon, south London
Ratana - who was just months away from retirement age - was hit in the chest and thigh
De Zoysa was left with brain damage after another shot struck his own neck, and communicated in court via whiteboard
Justice Johnson outlines that the starting point for murder of a police officer is a whole life order.
He says a minimum term order can be given depending on the case, and proceeds to outline the events of the night of the murder.
Justice Jeremy Johnson continues by saying he has taken into account medical evidence about De Zoysa's condition.
He also says he has been deciding between a minimum term order and a whole life order.
Justice Johnson goes on to lay out his sentencing options.
Daniel Sandford
Reporting from Northampton Crown Court
As has happened throughout the trial, Justice Johnson is using very simple language to make sure that Louis De Zoysa understands as much as possible.
Justice Johnson starts by saying Ratana "had devoted his life to public service, he had put himself in the way of danger to protect the public."
He is recapping the details of the case, and the impact of the Ratana family.
Daniel Sandford
Reporting from Northampton Crown Court
De Zoysa does not look like a person who fully comprehends that he is about to learn whether he will die in prison.
His parents, Elizabeth and Channa De Zoysa, look gaunt.
The sentencing of Louis De Zoysa by judge Mr Justice Johnson is starting now.
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Shortly, we expect to get the judge’s sentencing remarks live from Northampton Crown Court.
Our live page team has streamed several sentencings this year already, but it is still a relative novelty.
A change in the law last year allowed filming inside English and Welsh courts for the first time.
Scotland has been doing this for years.
Increasing public confidence in the judiciary process was one of the main motivations behind this change.
In England and Wales, only four organisations have permission to film - the BBC, ITN, Sky and PA Media - and they have to apply to the judge to film the sentencing remarks of a case.
Even then, broadcasters can only film remarks made by the most senior judges.
No-one else can be filmed. So cameras won’t be allowed to capture victims, witnesses or jurors.
Daniel Sandford
Reporting from Northampton Crown Court
Mr Justice Jeremy Johnson says "I will sentence at 12:05".
Daniel Sandford
Reporting from Northampton Crown Court
We are hearing some more from De Zoysa's barrister Imran Khan KC, with a statement from De Zoysa's mother, Elizabeth De Zoysa, being read out.
"We are focusing very much on healing and forgiveness because this is the only way forward."
She describes the effects on Louis De Zoysa's brothers and sisters who have struggled with mental health issues and education.
"The only message we can give our children is that Louis will spend his time in prison rehabilitating.
"It will be a life sentence for our children knowing that he will spend his life behind bars."
Imran Khan KC argues for a finite minimum term, not a whole-life order. He says: "There should be some hope."
We've just seen the prosecution's submission in writing, which outlines what lawyers believe to be the appropriate sentence for De Zoysa.
Given this is a murder charge involving a police officer, the prosecution is seeking a whole-life order, meaning De Zoysa would spend the remainder of his life in prison.
If the court considers the whole life sentence is not appropriate in this case, the prosecution has written, any minimum term imposed should be significantly in excess of 30 years.
This is to reflect the seriousness of the crime, the submission says.
De Zoysa's barrister continues by telling the judge: "This is not a case in which you should impose a whole-life order."
"There aren't factors which take you up (in deciding a tariff).
"There are factors which take you down. We say there are substantial mitigating factors."
Daniel Sandford
Reporting from Northampton Crown Court
Imran Khan KC goes on to argue that Louis De Zoysa made his decision to shoot a police officer while he was briefly in the holding cell (and not in the police van on the way to the custody centre, which was the prosecution case).
"Louis is not an evil man. He is not a wicked man. He is not a monster," he says.
"He is a troubled man.
"This court is not sentencing a neurotypical offender.
"These are factors that he had at the time of the shooting.
"That - we say - you can take into account in terms of his overall culpability."
Daniel Sandford
Reporting from Northampton Crown Court
After a short break, the court resumes.
Imran Khan KC, defending, is speaking for Louis De Zoysa.
He says the events of 25 September 2020 led to "a life lost, and a life destroyed."
"Louis De Zoysa's future will never be the same again," Khan adds.
He goes on to talk about De Zoysa's autism, "vicious bullying at school" and violence suffered at the hand of his father.
Khan notes, too, the defendant's "fascination for guns".
"The precise motive for why he shot Sgt Ratana may never be known," he says, and that "one may never know why he was carrying a gun".
You'll see from our coverage so far that there are important courtroom proceedings to get through before the judge gives his sentence - something that will be filmed and broadcast in a relatively rare spectacle.
A short time ago, we heard victim impact statements from some of Ratana's family members.
Mr Justice Johnson is now listening from both the prosecution and the defence in deciding the severity of the sentence he hands down.
During this time both sides are likely to be referring to sentencing guidelines, which broadly lay out the applicable sentence for different crimes.
It will then move to the judge for sentencing, which is what we will be able to watch today. The first televised sentencing at a crown court in England took place almost exactly one year ago, on 28 July 2022, when Judge Sarah Munro handed down a sentence for manslaughter at the Old Bailey.
The court has just had a short break, before hearing submissions from De Zoysa's defence team.
So far we've heard from the prosecution.
Make sure to stay glued to our live text coverage of proceedings at Northampton Crown Court.
The court has just heard some emotional statements prepared by Sgt Matt Ratana's family.
They come ahead of the sentencing of Louis De Zoysa, after a jury found him guilty of murdering Ratana while in police custody in 2020.
Daniel Sandford
Reporting from Northampton Crown Court
We just heard a series of emotional victim impact statements from Matt Ratana's family members - including from his partner, son and brother.
Louis De Zoysa, Ratana's killer, remained impassive throughout.
Su Bushby continues with her tearful statement.
"I am hoping that one day it will get easier but at the moment the nightmare continues," she says. "At this moment in time I cannot forgive him for what he has done."
"The person who shot Matt and ripped my life apart, my life as I once knew it.
The trial has taken its toll on me. It wasn’t easy, facing him every day in the courtroom, but I knew I had to do it for Matt. I felt emotionally drained every day at court."
Daniel Sandford
Reporting from Northampton Crown Court
Matt Ratana's partner is continuing with her statement, becoming tearful as she reads it out.
Here is some of what was said before the court.
"The tormenting grief was so overwhelming and the feeling of emptiness was so intense. I just sat there, waiting and willing him to walk through the door. I still do to this day," Su Bushby says.
"The last few years have been surreal. I remember seeing the man who shot Matt for the first time in November 2022, it was two years after I had lost my soulmate.
"I found it extremely difficult to face him because I remember thinking how unfair it was.
"I have been in a state of limbo since that day. I have not been able to get on with my life and wasn’t able to work for two years, I still can’t move on with my life after losing Matt and I don’t know if I ever will."
Daniel Sandford
Reporting from Northampton Crown Court
We are hearing from Su Bushby now, Matt Ratana's partner - who is in court to read her own statement.
She says losing him was the most devastating moment of her life.
"If he was alive today we would be celebrating eight years together," she says.
She describes being told by a police officer that Matt had been shot.
"My whole body just froze... I wondered if I heard him properly," she says.
"I can remember falling to floor, screaming and crying uncontrollably."
"I remember telling him that I wanted to see Matt; I wanted to be with him. I just had to get to him and hold him. I wanted to see if it was real because I didn’t want to believe what I had just been told."