Complex sentence: Thorn sees him and tries to pursue, innocent people in the crowd are killed by the would be assasin, when the assassin retreats he is is crushed under the scoop of a riot-control vehicle.
Split into simpler sentences: Thorn sees him and tries to pursue, and innocent people in the crowd are killed by the would be assassin. When the assassin retreats, he is is crushed under the scoop of a riot-control vehicle.