I don’t think it was a cop. My bets are on some deplorable hating Dem staffer.
The murderer may not have been a police officer and could be a man or woman. It could have been an aide or congress critter.
-The shooter fired at her when she had officers in tactical gear right behind her. It's a very incompetent officer who would take a shot with other officers right behind the perp.
--The shot was horizontal, even more a risk for the officers standing behind the victim. A trained officer in that situation would likely have used the chop-down technique, shooting down at an angle, dropping the perp down into the line of more lethal fire if needed but avoiding a horizontal shot. -The shooter used a single hand punching motion which points to an amateur. Such poor technique and lack of control explains how the shooter aimed for her head and hit her in the neck instead.
-The shooter fired point blank at a woman would could have been pushed back through the window, pepper sprayed, or even cuffed in place as she was trying to get through.
-Few trained individuals would take a shot that was clearly murder. This wasn't a double tap to the torso, it was a point blank shot toward the head. -Police officers are less likely to wear such cuff links.