Towards the end on the mission, once the officer grabs the intel/journal, keep following him. Eventually, he'll make his way towards a truck near some explosives and he'll start investigating the boxes. Blow the boxes up and you'll get the trophy. Alternately, as seen in the video, he may take a different path. Either way, look for nearby explosives and shoot them once he stops moving.
Credit goes to PS4Trophies for the guide.