You have to take anything the cop says with a boulder-sized grain of salt considering he was caught on camera planting evidence. His first shot was fired when the victim was some 15 feet away and his back to him. It's really hard to twist this into anything but cold-blooded murder.
And that is my view as well, not just regarding police officers but all public employees. Public employees have been demonized by politicians and had their pay and benefits targeted by legislators for far too long. We're expecting more work and knowledge while paying them less and less each year. Being a police officer is a professional job. It should be treated like that in terms of pay and benefits. Same for firefighters, school teachers, and all other public employees. Don't expect the best and most professional people for these jobs when society and government continues to treat them like s***.