Views.
Okay, not exactly "Let's start a race war for ad money", but they want views short term. That means scandal, gossip, drama. They also want to focus on "the narrative" which doesn't necessarily mean the far-left narrative, though it can be. Instead it's framing a news in a way that makes for a good story. The real world has muddy, complected morality that is boring to talk about. There's also the simple fact that most of the time there's fuck all happening worth talking about. A mass shooting like this can be milked for content for days, weeks, even months.