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I keep seeing mixed reports. Best I can figure from the news is an s&w m&p ar but that sounds like a pretty bottom of the barrel pick for an assination attempt.
Also, I am seeing 400 yards which would be possible for an ar but unlikely, based on the skill and accuracy of the population at my local range, especially if the person was non-military. Then, I see 150 ft. Which would be more realistic with a regular ar.