Why feel bad for the police. This has been going on for decades. The police is the victim of a system that they themselves helped to create. The system in a way is set up for the police to fail.
Why feel bad? That is like saying "Why have compassion for my fellow humans?" Police officers are aliens from Mars? Androids? They're human.
They train them to shoot to kill and when they do, well, they go to jail.
Police are trained to use deadly force to affect an arrest of serious felony offenses as outlined by the law. Firearms are deadly force because, not matter how you shoot someone, the risk of death or serious bodily injury is responsibly expect to happen.
Sometimes people don't comply because they don't understand what they have done wrong or why you are stopping them. Some police officers do a bad job of explaining the whys and hows.
In my 20+ years experience I have found that most people do understand. They just want to argue because they do not want to be held accountable. Even when explaining things in plain English they respond with "That's not right!" In other words, "I don't like that because I don't want to be held accountable."
If you want to fix the problem with policing, you need to take a step back and look at the structure. How many times have you heard a police chief talk about "only a few bad apples" but they do nothing to actively remove the bad apple (Police Union??) until it becomes politically or socially too hot.
If you want to fix the problem get to the root - systemic race based poverty and penalizing drug addiction. If generations of of people of a minority community lack education and employment opportunity while being surround by people who are living in excess, crime will happen. People suffering from addiction often resort to crime to feed their addiction. Instead of helping these people or government criminalizes this behavior and just incarcerates them. In addition, Police Unions get a bad rap for "protecting bad apples". The whole reason Police Unions started was because cops were used as pawns in elected officials personal vendettas. Local elected officials decided what laws to enforce and who was exempt from being held accountable. Being an honorable cop put one at risk for being fired for not being dirty. Just look at law enforcement agencies where cops are at-will employees and see the abuse they have to endure.
Why are they allowed to investigate themselves?
Law enforcement agencies are required to investigate their own officers for violations of agency policy and citizen complaints. Other agencies conduct investigations for crimes committed by police officers to make sure there is no conflict of interest.
Why does the camera stop working when the police is at fault and they refuse to release the footage to the public. A young girl was recently shot and the police promptly release the footage to show that the victim was at fault. That should be the standard approach to any type of incident that result in shoot at citizens. However, that is not often what happens.
Police are getting a bad rap now because of social media and smartphones which means more people are aware of when things go wrong.
Body cams and in-car video are tech - they do fail. My buddy's body cam failed. He was shot with a rifle. The bullet hit his body cam and ricocheted into his throat, killing him. They are also evidence. Publishing evidence prior to a criminal investigation being completed tends to undermine the investigation.
Social media and 24 hour cable news media is responsible for the bad rap police get as well as leftist, post modern ideology. There are over 500,000 law enforcement officers in America. Online news sources, social media, and 24 hour cable news inundate us with stories. One cop is all cops because no one is an individual anymore. We are all the group we get thrown into. Narratives are created to wrestle for control between groups. If the news were required to report on the activities of every cop in America everyday we would have perspective. Blood sells. Fear sells. Emotions are riled up to make sure reason and rationality go out the door.