Sheriff: Border Agents Likely Shot Using Military Grade Weaponry

One border patrol agent was killed, another injured, in the desert in the middle of the night

After Border Patrol agent Nicholas Ivie was killed and another agent was injured, questions are being raised about how smugglers and drug runners are able to attack agents in the desert during the dead of night. 

Questions like: How were shooters able to fire on those border agents, were they up close? What kind of equipment do smugglers and drug runners have? Are agents up against night vision or military grade equipment?