A teenager who murdered a 16-year-old boy with a zombie knife at a train station has been jailed for life.
Kion McKenna, 17, stabbed Louis Johnson to death by stabbing him once in the chest, but said he attacked out of fear he would be stabbed himself.
The court heard he later wrote a rap “bragging” about the murder.
McKenna insisted he was threatened on Snapchat, and pleaded guilty to having a knife but denied murder.
He was found guilty in September by an Old Bailey jury and given a minimum of 16 years on Friday.
Judge Mark Dennis QC said: “This was a shocking and dreadful display of violence for which there was no justification or excuse.
“This once again demonstrates how lives can be turned around by such youth gang violence.
“Though you were of a young age, you were old enough to know what you were doing and to make your own choices.”
The killer told the court he often carried knives, starting at age 13 to “look cool”.
Telling jurors he had encountered Johnson before, McKenna said the victim had made threats against him on Snapchat.
The trial heard that McKenna, who was 16 at the time of the murder, saw Johnson on the overbridge at East Croydon station just after 4.30pm on 27 January.
Johnson, who the court heard had connections with a Clapham gang, sustained a stab wound to the chest and was pronounced dead at the scene.
“I thought he was going to stab me. I put my phone in my pocket,” McKenna said.
“I saw him reaching for his waistband.
“I pulled out my knife and thrust it towards him.”
CCTV showed McKenna, who was linked to a Tooting gang, running from the station with knife in hand before going to Chichester, where he was seen on CCTV smiling and dancing in a takeaway.
He had shaved his long hair off to attempt to disguise himself but handed himself in to police two days after the killing.
A knife matching the description of the blade used in the killing was found in a Tooting chicken shop.
A zombie knife is defined in law as a blade with a cutting edge, a serrated edge and images or words suggesting it is to be used for violence.
The Old Bailey heard a week after being remanded in custody, McKenna created a rap, referencing the victim’s death, saying he was “coughing up blood”.
Judge Dennis said: “The evidence that related to the defendant’s conduct following his arrest and remand in custody – composing and sharing rap lyrics appearing to be him bragging about the killing, supporting and encouraging gang violence – demonstrated he had little concern hitherto about publicising his actions.”
Johnson’s mother Natalie Secka said her family’s life “has not been the same” in a statement, saying he was a “good son” and “kind, polite and overall was willing to help others”.
She added: “We will never get over losing Louis, never. Nobody deserves to be stabbed by such a terrifying weapon and left to die on a cold, wet train station floor.
“As a mother, that thought of your child dying terrified is too much to bear.”
Watch: Can you catch the coronavirus twice?