The following section of the guide to Marvel's Spider-Man contains a breakdown of another side quest about finding students: "Over his head".
Mission's starting location: Greenwich
Reward: 1500 XP.
You will have to find another missing person. The name's Steve Hopkins. You will get a picture showing him in a park. Peter has identified the location as Upper West Side. Look at the screen above - it shows the exact spot.
Enemies await there. The best idea is to defeat them quietly - they're patrolling the area separately, so it shouldn't be really difficult. Try to cope with all the patrolmen, and you will find Steve. He's been turned into a zombie - a few good punches will let him get back to his senses. The quest will be finished and another part of this storyline will be unlocked.