1) Sometimes police shootings are justified and sometimes it's a tragic misunderstanding. On very, very rare occasions, police have knowingly committed murder. These cases are very difficult to investigate because they involve suspects who know how police investigations are carried out.
2) Peaceful protests are great, rioting is bad.
3) Arresting rioters is great, arresting peaceful protesters and journalists is bad.
4) Police officers are civilians, and should not have weapons that are prohibited for civilian use.
5) Here's an idea: All funding for state and local law enforcement should come from the state and local level. If voters in a jurisdiction won't support a bond issue or tax increase to spend $500,000 on an armored vehicle, then maybe the police shouldn't have that armored vehicle. Maybe an MRAP designed to protect its crew from a roadside bomb belongs in the Mideast and not the Midwest.