A third arrest has been made after a 21-year-old man was stabbed to death at a London shopping centre.
Gedeon Ngwadema was attacked at Brent Cross mall at 6.45pm on Tuesday after reports that a fight broke out.
A post-mortem examination revealed he died from a single stab wound despite efforts to save him.
Met detectives say Gedeon’s family are experiencing “unimaginable grief” after the tragedy.
His mum, Thethe Elonga, laid flowers for her son on Wednesday morning when she collapsed and broke down in tears.
She told the Standard: “I’m heartbroken. He was a wonderful boy, respectful and lovely. He did very well at school and had a very bright future ahead of him.”
On Wednesday, officers arrested a 20-year-old man on suspicion of murder at his home in Harrow, north west London.
It comes after an 18-year-old man was arrested on suspicion of murder and another male, aged 22, was arrested on suspicion of murder and affray on Tuesday. All three men are in custody.
A crime scene remains in place at the shopping centre, and police have warned the public to expect to see an increased presence of officers in the area.
Gedeon’s family said he had returned home after shopping with his mother before receiving a call from a friend. He went out and they never saw him alive again.
Footage shared on social media showed police escorting shoppers out of the building and an air ambulance landing in the empty car park.
A security guard in the Apple Store said: “All the security came straight away, then the police arrived and they closed the whole floor.
“The police were chasing them to the parking lot because they thought the attacker was there.”
A defibrillator was used on the victim as he lay dying outside Marks and Spencers, witnesses said.
DCI Linda Bradley, leading the investigation, said: “There was a significant number of people nearby when this tragic incident happened and I am confident that there are people out there who are yet to come forward.
“No matter how insignificant the information may seem to you, please contact the police as soon as possible.
“As you can imagine, Gedeon’s family are experiencing unimaginable grief and we want to bring answers and justice to them as quickly as we can.
“This is a complex investigation and we appreciate the local community’s support and understanding while we continue to conduct our inquiries.”
The force are urging anyone with information to come forward.
DCI Bradley said: “We are directly appealing for information from anyone who may have witnessed the incident and is able to help us with our investigation.
“We are especially urging anyone with footage of the incident or the aftermath to get in touch with us immediately.”