Most security agents are seen in movies making a line while conducting raids.
Well then, the line does not form by accident nor is it fictional.
This is the same thing that happens with the Kenyan Recce Squared when it conducted a raid on attackers such as Al Shabaab.
The line itself is referred in the military term as a snake.
According to Howstuffswork, the single-file line has worked pretty well to minimize injuries on the security officers when the suspects shoot as compared to when security agent was dispersed.
The tactic only put one of the members of the team who is in front at risk.
The person in front is commonly known as the point man.
He is highly trained and makes the lead and other important communication on behalf of the rest of the team.
The point man usually enters the room first after members of the team has helped him break the door open.
The man makes the decisions of life and death. He needs to face any suspect that he will encounter in the room. He determines whether the person rushing to him is a suspect or not.
He questions attackers on behalf of the team.
Once they enter the room, the game changes. Each member takes a different position to prevent one from standing in the way of another person during a battle. Here, they need to quickly take control of the room before heading to another one again in the single line.
Sometimes, the members of the team make a bang on the door before entering usually to disorient the attackers or suspects.