When an officer has a citizen encounter they should consider their "tactical position." We all have been trained to maintain some distance from the citizen/suspect. This is to allow reaction time in the event of an attack. Typically six feet is a good distance or the two-arms-length rule should be employed for an unarmed encounter.
I think we should go beyond this and train our officers to consider other factors.
The environment is a key consideration.
Conducting the encounter in the safest location is overlooked frequently. Unfortunately officers get wrapped up in the moment and forget to move out of harms way.