Modupe is a security guard seen in the mission Final Interview in Grand Theft Auto IV. If the player waits long enough without attacking Goldberg, he will call Modupe saying that Niko is wasting his time. Goldberg will ask Modupe to remove Niko from the building. Instead of this Modupe pulls out a gun and starts to shoot at Niko.
It is unknown why Modupe attacks Niko instead of throwing him out. It is likely to make the mission slightly harder and to prevent the mission from failing by getting Niko thrown out of the building. It can also imply that Modupe has mental problems, which could explain his behavior towards Niko.