This is the recruitment mission for bonus character Gat, hero of the Saints' Row games. Unlike the other recruitment missions, there's no special investigation beforehand.
Touch the marker in the transfer station to immediately begin his solo mission.
Your first infraction to investigate: littering. Drive over, survey the untidiness, and get ambushed by LEGION. Kill 'em all, and get cosy with Gat's slug thrower.
When all enemies are down, drive to the objective, an illegally parked vehicle with a bitchin' (and vaguely familiar) paintjob.
No owner nearby, but waves of LEGION will materialize and attack- first a small wave from the road, then a much larger wave from the buildings behind you.
Use your special to clear the field, then blow up the van for good measure.
The next stop- apprehending a public urinator, turns into a showcase for your mayhem ability, which your gives you autolocking deadly accuracy on anything nearby.
A good way to mow down scattered mooks, but be sure to use it when you're not in immediate danger from a heavy. When these guys are toast, head to your final objective, amongst stacks of shipping containers.
This kicks off a massive ambush, capped by Blitztrooper Commander. Best strategy is to go low, and turn some relatively securable corridor into a killzone.
A little more dialogue closes out the mission, and unlocks Gat for your roster.