There's a Standard article but I don't know how to transfer It. Search .. Seven Sisters shooting.
That article was from March 2018
Ah yeah, and that article seems to be where the person from Twitter is getting their information. So I guess it wasn’t a 14 year old being shot, and we don’t know what happened yet
There was notable blood trail from opposite the big Tesco on Seven Sisters Road down to the corner of West Green Road and Seven Sisters where a big pool had settled with spatters. I noticed it later after the road was re-opened. Not sure if it's related.
I googled all that day to try and find out what was going on to no avail. It will remain a mystery...?!