This is not yet a fully-formed thought but it keeps coming up for me: Domestic violence experts warn that in abusive relationships, strangling / choking / restricting a victim's airway is the one act that best predicts murder down the line.

Choking someone isn't just a thing that happens. It's its own category of violence. The neck is a vulnerable place; we all instinctively protect ours. When a person grabs another by the neck, or presses their knee into someone's neck, that's not restraining them or fighting back.

People (usually men) who go for their partners' necks are the most lethal abusers -- the most likely to eventually kill their partners. It's about immediate life-threatening dominance: I can end you. Too often, they eventually do. The parallels to police violence are clear.

There are a lot of ways to restrain a person, but digging your knee into their neck and cutting off their airway is a choice. It's a choice that in and of itself reflects a total disregard for human life, and indeed a level of intentional malice and lethality.