It took CNN three days after the video was already circulating and getting huge traction; before they reported on it themselves.
four days for NYT.
This is after the video had already been circulating for days and received a lot of attention, the killing happened on August 22nd and the video has been going around since the 5th of september: https://www.mediaite.com/media/conservatives-call-out-media-...
These same outlets reported on George Floyds death effectively immediately.
Mark Duggan was shot in London and the US MSM picked it up faster.
Not aware of anything regarding local news, but when one killing reaches international news and the other has to be already organically international news via social media before reporting happens: people start to make presumptions.