So, until we can convict a white cop without having to have a perfect storm of evidence and witnesses; until we can reasonably expect to get a fair outcome EVERY TIME a cop is indicted...
The outcome was a good, and fair outcome in my mind. However, for what you are hoping for (in blue) - unless a murder is clearcut, it is very difficult to get a convication against anyone
. That's the way the system was designed. Lots of murderers are let go for lack of evidence. Some even then use the verdict to proclaim their innocence (when the verdict really should be interpreted as 'unable to be proven beyond reasonable doubt'). This is how the justice system was designed, so that innocent people don't get convicted. Unless it is very clearcut it is even more difficult to convict a police officer - for very good reasons related to dynamic/volatile interactions.
That is to say, while I would hope that all murderers get convicted so that the victims family can obtain a sense of justice - but it's (usually) way more difficult a situation than such. As a reminder, I see this conviction as a fair outcome.
There does seem to be a real problem in the US