A 24-year-old man was arrested on suspicion of murder on Monday, 13 March. He has since been released under investigation.
Corey Junior Davis was shot in the head in a playground in Moore Walk, E7, at around 3.08pm on 4 September 2017.
The 14-year-old, who was also known as CJ, had been socialising with a friend when the shooting happened.
He was taken to hospital but died the following day.
Detective Chief Inspector Dave Whellams, from the Met’s Specialist Crime Command, said: “This is an important development in our investigation and demonstrates our commitment in our pursuit for justice for CJ and his family.
“We have informed them of this arrest and will continue to support them as our enquiries continue.”
The investigation continues and anyone who can help officers is asked to contact the incident room on 020 8345 3775.
Information can also be provided anonymously by calling the independent charity Crimestoppers on 0800 555 111.
