If I put someone I’ve argued with in my car and drive around for a while and that person dies of trauma, it doesn’t amount to criminality? Or is that assumption accorded only to police?
It’s very difficult for me to understand what aspects of this situation are confusing to you. You surely understand that if you put someone in your car against their will, regardless of whether there was an antecedent argument, that’s generally going to be the crime of kidnapping. You have no legal right to put anyone in your car, as a general rule, unless they wish to be in your car.
The police, on the other hand, are not kidnappers when they effect a legal arrest.
Do you understand this difference between you and the police?
If you do, can you explain what motivated you to ask the question you did?
No, it means there was not enough evidence to convict. In a civil case, it would not have been difficult to prove liability. This was not a civil case. We can be almost certain that one or more of the officers’ actions did amount to “criminality,” since a generally healthy man had his neck broken while shackled and in police custody. We just can’t convict anyone.