A teenager who stabbed his friend to death can be named for the first time after an order granting him anonymity was lifted. Joshua Molnar was cleared of the murder and manslaughter of 17-year-old Yousef Makki after a jury accepted that he knifed him in the heart in self-defence.

In a statement, his mother, Stephanie Molnar, said the teenager “fully accepts responsibility for Yousef’s death in the act of self-defence and the impact of this acceptance is massive”.

However, Makki’s family claimed they had ‘‘never seen a shred of true remorse from Joshua Molnar”, or the second defendant, known as Boy B, who was not charged with, or ever accused of, murder or manslaughter, and was sentenced to a four-month detention training order after he pleaded guilty to carrying a knife in an incident earlier that day.

Yousef Makki. Photograph: AFP/Getty Images

Makki, who dreamed of becoming a heart surgeon, was killed in March in Hale Barns, an affluent suburb of Greater Manchester. Raised mostly by his single mother, Debbie, on a council estate in Burnage, south Manchester, Makki was from an Anglo-Lebanese family and had won a scholarship to attend fee-paying Manchester grammar school.

Molnar, previously known as Boy A, turns 18 on Tuesday. He was sentenced to a 16-month detention training order in July after admitting perverting the course of justice and possession of a bladed article.

His mother, until recently director and co-owner of a successful nursery business, told the Sunday Times magazine in an extensive interview that the case had been traumatising for all the families involved. The magazine legally challenged the anonymity order with agreement from Molnar and his family. On dreaming of being a normal family again, she said: “And then you remember they [Yousef’s family] haven’t even got that chance, and you just feel very selfish for even thinking about it.”

In response, Makki’s family spoke of the “utter devastation” on their lives, adding: “The injustice of everything will remain with us forever.” They maintain that they do not accept that his death was an accident.

During the trial, Molnar admitted to having a knife on him. He told the court that, following an argument between the boys after a botched attempt to buy drugs, Makki had pulled out a knife and so he had pulled out a flick-knife in return. Molnar testified that he did not know how he ended up stabbing his friend. Makki’s family have always maintained there was no DNA or other independent evidence that Yousef had a knife, but the assertion was accepted by the jury as part of Molnar’s self-defence claim.

When Molnar was cleared of murder and manslaughter in July, there were angry scenes in Manchester crown court. Makki’s father, Ghaleb Makki, collapsed after shouting: “Where’s the justice for my son?” Jade Akoum, Yousef’s sister, previously told the Guardian the family were made to feel “like criminals” during the trial, as they were asked to sit in the public gallery while the relatives of the defendants – both from middle-class Cheshire families – were given priority seating in the courtroom instead of the victim’s family.

In response to media reports of Stephanie Molnar’s words, the former chief prosecutor for the north-west, Nazir Afzal, tweeted: “This is offensive to the family of the boy that was killed. Can you recall last time a killer (he’s not a murderer) was given a page with a sweet picture to talk about why he did it? It smacks of white privilege.”

The case ignited a heated debate about class and race in the criminal justice system. Lucy Powell, MP for Manchester Central, asked in a tweet following the acquittal whether the jury would have arrived at the same conclusion if “these defendants were black, at state school and from, say, Moss Side” – an inner-city Manchester borough historically home to the city’s Caribbean population. When challenged on whether she had sat through all the evidence in this case, Powell said she was making the wider point that research showed black, poor, young men were much more likely to receive harsher sentences for “a peripheral, if any, role in a killing”.

During the trial, Molnar filmed himself in the court building making stabbing motions to the soundtrack of a drill track with the lyric “two flicks with my hand, let’s see who bleeds”. The video was widely shared on social media and sent to Yousef’s younger brother following the verdict. Following a complaint from Makki’s family to the judge and police, lawyers for Molnar told the Guardian the video was “intended as a private message” for the teenager’s girlfriend only and “reflected his frustration with the way the prosecution were misrepresenting videos that were played out at court”. They said it “does not reflect lack of remorse on his part”.

His mother said he had told her he was always reliving the incident and could not get the image of Yousef dying in front of him out of his mind.

Makki’s family told the Guardian that the Molnar family’s words “show a huge sense of denial from the parents”. They added: “The way they treated us in court and afterwards shows there is no true remorse, so no chance of forgiveness from us, if that is what they are seeking.” They vowed to keep fighting for justice for Yousef and are crowd-funding to seek civil action.

They said: “In his memory, we will not rest until we have done so. We miss Yousef every second of every day. The past seven months have been so traumatic and heartbreaking for us all.”