The veterinarian gun type is an odd choice, so we know it has meaning for Depose, Deny, Defend.
Monopoly money in the photographer brand backpack sold from 2016-2019 means something, as does the dropped phone, and the drink container carefully placed on top of the garbage bags in clear view of a camera.
Is the shooter treating an health care executive like he thinks executive health care treats clients? Like taking a bolt to the brain?
Where did he get the veterinarian gun? Did he inherit it? Does he have one for work, or he knows someone and stole it? Maybe he bought it, but it sounds somewhat restricted to veterinarians, farmers, ranchers, and field hands.
I know nothing about guns. I hope I interpreted the gun info correctly.