Yes. if multiple officers are handling the gun with out gloves they are putting their fingerprints and dna on the gun which can either smudge other fingerprints and wipe other dna off
At the time, the US was trying to practice Isolationism. They refrained form signing the treaty of versailles, and thus were never involved in the League of Nations.
Donald Broadbent would attribute this to his theory of attention called the filter model of attention. The filter model of attention states that stimuli can be filtered or selected to be attended to during processing. The stimuli can be filtered based on pitch or direction of the stimulus.
I think that the answer is a because than they can pass laws when other can't and they can have their own rules.