Police have appealed for a key witness to come forward after the fatal stabbing of a man in Primrose Hill on Tuesday.
Finbar Sullivan, 21, died after being stabbed at the popular viewpoint, and now Met detectives are looking for a young woman or teenager who may be able to help solve the case.
The girl was captured on film recording a fight in the park, which is believed to have occurred shortly before the incident.
Footage shows her wearing a pink vest, blue denim shorts and black trainers.


Police believe the footage she filmed could be vital in assisting their ongoing enquiries and will help officers piece together the sequence of events.
The Met emphasised that she has not committed any offences and is being treated as a significant witness.
Detective Inspector Andy Griffin, who is leading the investigation, said: “My team continues to pursue several urgent lines of enquiry to establish why Fin tragically lost his life.
“I believe this woman’s account of events, as well as the video she captured, will provide vital evidence. To reiterate, she has not committed any offence but we are urging her, or anyone who may know her, to come forward and assist our investigation. We need to speak to her as soon as possible.”

Police received reports of the fight at 6.41pm, and upon arrival found Finbar with stab wounds.
Despite the efforts of emergency services, he died at the scene.
Another man, believed to be in his 20s, was found nearby on Regent’s Park Road and was taken to hospital with stab wounds, which have since been confirmed as non-life-threatening and non-life-changing.
No arrests have been made at this stage, while the investigation continues.
Finbar has been remembered by friends and family as a “beautiful, lovely, outgoing, loving boy”.

He was a filmmaking student, and was reportedly on the hill to try out a new camera he had received as a birthday present.
His father, Christopher Sullivan, told The Telegraph: “He doesn’t go out. He just stays in. He goes and does his shoots and edits his videos… He doesn’t drink and he’s not that type of person, he’s here six nights a week.
“There’s an audience out there that should be aware that this can happen to anybody, white or black, in the most upmarket area. It’s a warning to us all.”
The witness in question or anyone with information can upload information to the police major incident portal, or contact police on 101, quoting reference CAD 6448/07Apr. An anonymous report can be made via Crimestoppers on 0800 555 111.
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