Shawn Seesahais 12-year-old killers sent chilling Snapchat messages to each other the morning after the brutal machete attack, including one that said of the murder: It is what it is.
Two boys, now aged 13, received life sentences with a minimum of eight and a half years each at Nottingham Crown Court on Friday, after being convicted earlier this year.
Shawn Seesahai, 19, was killed during a confrontation over a park bench in Wolverhampton on November 13 last year.
Britains youngest knife killers punched, kicked, stamped on, and hacked the innocent teenager to death with a 16-inch machete in a random and unprovoked attack.
After their conviction, social media exchanges came to light involving them and a girl witness who later attended a police station with her mother to make a statement.
The Snapchat messages the two killers sent to each other after they killed Shawn Seesahai
The conversation retrieved by police starts when one of the killers says on Snapchat of the stabbing: Everyones talking abt (sic) it, literally everyone, everyone knows.
The other one in the pair, who were both found guilty of murder at Nottingham Crown Court in June, then responds with a voice note, saying: It is what it is.
They then shared more messages, saying: Im scared man - before the other says Im not, followed by the acronym IDRC, which means I dont really care.
The other one then responds with a voice note saying: I aint said nowt (sic) cause every time I talk about it, like I act weird apparently so (inaudible) comes and goes.
There is then a response saying: Im just scared your you too (sic).
The boys sentences mean they will remain in custody until they are at least 20, and it includes time living in secure accommodation, where they have been since the offence last November.
Mrs Justice Tipples told the killers: What you both did is horrific and shocking.
You both killed Shawn in an attack that lasted less than a minute when he asked you to move from where you were on a park bench.
Shawn did not deserve to be attacked. He did not deserve to die… Its clear that the sentence I have decided to pass cannot make that right.
She added: What you did in those few short moments has also changed your life forever. You will have to live with the consequences.
I cannot be sure which one of you stabbed Shawn. Only you know that, but you acted together.
The boys, both wearing shirt and ties and one in a waistcoat, were allowed to sit in the well of the court as they had throughout the trial.
The judge also told the boys: When you killed Shawn he was 19, starting out in his adult life with everything to live for.
His parents have lost their son. His sister has lost her brother.
The victim, Shawn Seesahai (pictured), was shoulder-barged by the smaller of the two defendants before being punched, kicked, stamped on and chopped at with the weapon
One of the 12-year-olds found guilty of murdering Shawn Seesahai even posed for a snap with his machete tucked into the top of his trousers hours before he committed murder
In June, both boys were found guilty of murder and one guilty of possessing a bladed article.
They are believed to be youngest defendants convicted of murder in Britain since Robert Thompson and Jon Venables, both aged 11, were found guilty in 1993 of killing two-year-old James Bulger.
In an interview released after the verdicts, Mr Seesahais parents Suresh and Maneshwary have said they will never be able to get over the loss of their son, who always told them he would shine and take care of them.
The victims father Suresh Seesahai said: Losing a child is a parents worst nightmare.
It has left a huge hole in the pit of our stomach which nothing can fill, we are devastated as a family, totally heart broken and confused.
Chief Superintendent Kim Madill who is West Midland Police lead on serious youth violence, said: Shawns murder was horrifying, leaving his family understandably heartbroken and mourning their beloved son, and our thoughts and sympathies will remain with them.
Todays sentence can never make up for Shawns life being taken, but we hope it can bring some comfort to all those who loved him.
Shawn was only 19 when his life was taken at the hands of two boys, then aged just 12, who had armed themselves with a machete. That reality has had a huge impact on us all – it is both shocking and saddening.
The impact of knife crime is devastating and no matter where you live in the country, this is an issue which affects us all.
In the trial, it was heard how Mr Seesahai was shoulder-barged by the smaller of the two defendants, who often carried a machete with a 42.5cm-long blade.
He was then punched, kicked, stamped on and chopped at with the weapon.
The victims friend told the trial he was forced to run for his life but Mr Seesahai stumbled as he tried to flee from the boys on Wolverhamptons Stowlawn playing fields on November 13 last year.
After refusing to answer police questions in the aftermath of the murder, the boys both gave evidence to jurors, blaming each other for inflicting the fatal blow.
As well as failing to summon help for Mr Seesahai, the youths showed no remorse for what they had done in the 24 hours before their arrest - with one cleaning the machete with bleach and hiding it under his bed.
An image retrieved from a phone of one of the boys showing long knives and swords on a bed
CCTV footage revealed the last moments of Shawn Seesahai as he headed to the park
They told the court they both played video games in the hours after the killing, claiming they did not know Mr Seesahai had died until the following day.
Jurors heard one of the defendants posed, wearing a mask, with the murder weapon for a picture hours before the killing, and was found to have 11 areas of bloodstaining on his clothing.
The boy was also seen with blood on his hands in the aftermath of the murder, while his friend had a small area of bloodstaining on his right trainer.
Mr Seesahai, a stranger to the two boys, was pronounced dead at 9.11pm after police and paramedics were called to the scene.
Locals living near the Wolverhampton park where the 19-year-old was stabbed to death told of how one of the tearaways was a nasty piece of work.
Residents accused him of posting fireworks through letterboxes, damaging streetlights and stealing scooters in a reign of terror that plagued the neighbourhood.
One neighbour said the killer would ride across the playing fields on his mountain bike and hang around at night outside shops and alleyways where he would cut the wires on lampposts.
West Midlands Police said that on the night he was killed, Shawn and two friends travelled into Wolverhampton on the tram so one of the friends could visit his girlfriend.
Mr Seesahai, who had been living in Birmingham, had only been in the UK for about six months, having come over from his home in Anguilla for eye surgery.
While he and one friend waited on a bench in Stowlawn playing fields, some youngsters, who had been on a nearby basketball court, came over and the exchange resulted in Shawn being fatally stabbed.
Police were called to the scene and carried out CPR before paramedics took over. but Mr Seesahai was declared dead at 9.11pm.
Neither of the boy killers can be named for legal reasons.