He continued: “It was just a load of kids having a really good laugh, making their music video and they were just doing that for a while. It was really good fun.
“Then about an hour later we were just out here on the balcony having our tea, a drink or whatever, and we just heard shouting and some sort of shouting in the distance before the lads ran away.”
The man said that a short while later he looked out of his window and saw paramedics attempting to revive a young man lying on the ground.
Another resident, who also wished to remain anonymous, said: “I went to work about 11.15pm, and there was a group of maybe 20 to 25 lads…
“They were reasonably subdued…Normally, I ride my bike to work and I’d get on my bike down the bottom of the stairs, but I looked and I saw they were just starting to throw water bottles at the wall and they were just starting to get a bit boisterous.
“I came back around 2.20am and there were cordons and the tent was there.”
A section 60 order has now been put in place granting police extra stop and search powers following the killings which have rocked a community “rich” in spirit, detectives said.
Speaking from the crime scene, Jack May-Robinson, neighbourhood superintendent for Islington, said: “The families of both victims have been notified and they continue to be supported by specialist officers.
“I asked that their privacy is respected as they come to terms with this indescribable loss.”