Why are police in charge of investigating themselves during abuse of power investigations?
Christopher Hawk, 20-year police patrol veteran
Many agencies will not investigate their own incidents, including anything from a car crash involving a squad car up to a use-of-deadly-force incident. If there is more than one agency working in a particular area, it is just "good business" to bring someone from another agency in to do the investigation.
In smaller agencies, or in very rural areas, there simply may not be any other agency immediately available to do the investigation. While this may make things difficult in lesser cases (such as a fender-bender with a squad car), it works against the agency in high-profile cases. Not only are there recognizable conflict-of-interest issues involved with investigating your own people, but the smaller agencies may not be technically equipped to handle a significant case. Even many middle-sized departments will call in State or Sheriff's Department investigators to assist with these types of investigations.
Many people, however, will say they don't trust any police agency investigating an incident involving any other police agency. While the days of the Blue Wall and Thin Blue Line may not be completely erased, there are still issues involved in bringing in someone with no police experience at all to "investigate" an allegation of "abuse of power."
For instance, most Average Citizens don't have much knowledge or expertise in "Search and Seizure" (a general, broad topic involving search warrants, Fourth Amendment protections, seizure of property pursuant to {or without} warrants, etc). Search and Seizure is constantly evolving through various statutes, case law, etc. How do you make sure that a Citizen's Review Board understands the intricate nuances of Search and Seizure when they're trying to determine whether an officer "abused his power" by searching some particular person or place without a warrant?
Use of Force is another area where there are many, many complaints about police tactics. It also encompasses a wide array of other legal intricacies, and usually involves issues that are not quite as cut-and-dry as many people think. Just in Quora, we'll see huge disparities in how people may view a particular video or react to a particular new story, and they may form very strong opinions on law enforcement just from those stories. Unfortunately, it's not usually as easy as just watching a video and saying, "That was wrong," or, "That cop should be in jail." If the people who are investigating an incident can't separate their emotional responses about the incident from a review of the actual legalities involved, they shouldn't be involved in that investigation.
I will be the first to say I support the concept of Citizen Review Boards, as long as the people involved are willing to take the time to study police tactics and legal doctrine. I also believe that Blue Walls and Thin Blue Lines should be eradicated.
Officers who truly abuse their authority shouldn't be cops -- they make my job harder. But the unfortunate, ugly truth of policing is that it's not always "Officer Friendly" activity. Police have a very specific, difficult job to do. They are usually present when someone is experiencing some sort of crisis event and there are lots of things happening that influence how police respond to any particular situation. Until humans are taken out of the equation, there will occasionally be mistakes made by the people involved, but there will always be someone who is unhappy with the results.