an antigovernment protester.

[gunshot]

It marks a major escalation:

The first time an officer fired a live round

at a demonstrator

since protests began almost four months ago.

The scene was chaotic

and captured on camera from various angles.

We analyzed the footage to paint a comprehensive picture

of what exactly happened.

Let's take a closer look: It's China's National Day.

Hong Kong is engulfed in protests.

In the Tsuen Wan neighborhood,

a group of 15 protesters

approach officers in riot gear.

They start chasing and attacking

one of the officers with umbrellas and what

appear to be metal rods.

The officer falls to the ground

and protesters continue to beat him.

We see one man swinging a hammer,

and another person is holding a wrench.

Police deploy tear gas.

From this angle,

we see an officer running up to the chaos

with his revolver already drawn.

A shot rings out.

[gunshot]

Here is the scene from another angle.

We see the protester who's about to get shot.

He's carrying a blue shield.

The officer shoots him just as he's

swinging a metal rod at him.

He stumbles and falls over the officer on the ground.

The group scatters.

One protester attempts to help the victim.

He is tackled to the ground by another officer.

A person dressed in black, who appears to be a protester,

throws a Molotov cocktail at the officers from afar

and then flees.

We see at least two officers

have their guns drawn.

Another one holds a pepper-spray can

threatening those nearby.

Only now does the officer who shot the protester

put his gun away.

Note that he also carries nonlethal weapons.

He's holding a shotgun, which is likely loaded

with rubber bullets,

and has pepper spray in his holster.

The protester who was shot remains on the ground,

seemingly conscious.

We don't see any of the officers

provide first aid at this point.

According to U.N. basic principles,

officers should only use firearms

under imminent threat of death or serious injury,

and they need to give a clear warning of their intent

to use a gun.

The officer in the video does not

appear to warn the protesters that he is going to shoot.

Police said that one protester had

tried to stab the officer on the ground

with a sharp object and that police had warned protesters

to stop.

They defended their officer's decision to use live fire.

Police said that the 18-year-old protester

was shot near his left shoulder

and was taken to the hospital.

The incident marks a clear escalation in police

response to the protests and is sure to fuel more unrest

among the people of Hong Kong.