Where is the evidence that he was brandishing a knife at the police? Where is the evidence that he attempted to stab an officer?
Quit moving the goalposts.
I never said he tried to stab the police--I see no indication he did. I said we have a photo with the knife in his hand. It's close to his body, he's not going after anyone with it.
He's basically playing porcupine here but then he went for his car. To escape, to run over officers with, or because it held a better weapon? The officers have no way to know, they do know they're trying to serve a felony warrant on someone engaged in armed resistance, there's no reason to bet their lives on his plan being to escape. (And allowing him to escape with kids in the car is a bad idea anyway.)