Help the passengers who are still on the bus.

Even knowing that the villain is escaping, you know that you need to assure the safety of the innocents. You confirm that everybody on the bus is well first. There are plenty of bruises, a couple broken bones, but everybody seems okay and paramedics are on the way. In the meantime, the bad guy is gone and it's up to you to find him.

Interrogate the commuters for anything they might have witnessed. Look around for any clues left behind. Let the police handle this one.