Question

Through the crowded corridor, down the stairs, and out into the street. The police officer pursued the fleeing suspect.

Answer 1

i have to say it's an fragement. so i need to put the , in front of the

Answer 2

I would flip the two fragments: "The police officer pursued the fleeing suspect through the crowded corridor, down the stairs and out into the street." This places the subject taking the action before the action itself, which is easier to read.