No because of what @elbanditoroso said.
Body cameras don’t always show the full story. There are issues with placement and potentially audio, its technology and it fails. I would say that it would be incredibly rare to find footage recorded by a random citizen that not only shows the altercation/crime/whatever, but also shows the before and after. Most videos I’ve seen start off with an altercation between civilian/officer and not the full lead up to it.
Eye witness is also not 100% reliable. They can lie too, or just be wrong because things happen so fast their brain makes stuff up to fill it in.
It was explained to me in my classes that an officer writes a report, a supervisor reads in, and depending on the situation it gets sent to the DA so they can decide to move forward (Obviously they also look at evidence). So officers telling huge lies are unlikely to get away with it unless the department is in on it.
Police report is a vague term. Do you mean reports in which an officer may have had to use for or something? or do you just literally mean every police report that gets written? Because both need to be considered in court. They give a detailed, chronological explanation of everything that happened, and they include details on how people were acting. That stuff is key in certain cases so it needs to be admissible (For example, the body language and such of the spouses in a DV case, both the person whose been abused and the abuser. Little details like that which are included in reports is important).