For a start the media should focus on exposing inadequately prosecuted cops that broke the law instead of focusing on qualified immunity after the system already failed.
One way to actually fix the problem is external investigation of police complaints and the power to press charges separate from the DA. The vast majority of the time the people investigating a police shooting work in the same building as the shooters, and are often police themselves. Then the DA, which works with the police on most of their cases, ends up being the one that has to prosecute them. These should both be considered conflicts of interest. We need people that aren't friends with the cops to have the power to do something. The investigators should be limited to bringing criminal charges to police that must be tried in court to prevent abuses of their power (otherwise we risk a situation of "who watches the watchmen of the watchmen"). The idea of special prosecutors exists, but for some reason isn't applied to police matters.
Police unions are a problem now, but only because they have the power to fight a police chief over employment terms and threaten to strike. They would not be able to fight the prosecutor from an external organization. Let them fight the police chief over administrative actions and discipline for minor violations all they want (that's what unions are for) as long as punishment for crimes is handled by someone else. This is exactly how it works with every other union- they can fight employers on all sorts of matters, but they don't get a say once a member commits a crime, and police unions should be the same.
Also, with police matters, a lack of evidence should be viewed as suspicious, and possibly considered as supporting evidence for a complaint. The police should wear cameras but they shouldn't manage the recordings. Body cameras should be allowed to be turned off to deal with sensitive issues, but those occasions should be limited and reviewable. If a cop is about to go talk to a rape victim, then the footage leading up that point should be reviewed. If a body camera was turned off when someone filed a complaint about assault, it should be pretty easy to look at the footage leading up to that point and determine if the camera was turned off for an appropriate reason, or if the cop turned the camera off so they could crack some skulls without being recorded. Excuses like "I forgot to turn my camera back on" can be handled with indicator lights and audible tones or having the camera turn back on after a while. Excuses like "my camera stopped working" can be checked to see if the police officer submitted a service request.
None of these issues are controversial. The controversial part is that it costs money to set up an oversight investigation. Usually a politician running with a platform like this is doomed to lose an election because they are talking about raising taxes and they won't have the support of the police union. But if there were ever a time to get this implemented it would be now.