The death of a man

He sat there, eyes grown wide,
Because of him, a man just died.
He pulled the trigger and made the shot,
Without even a second thought.
He was alone,
When the man entered his home.
He ran out to find the source of the noise,
Now he realizes that wasn't a good choice.
The young man was made a killer,
And now he's about to loose his dinner.
He knew he had to stay strong,
But he thought what he did was wrong.
He looked up to see a bunch of cops,
One told him that the man robbed several shops.
The cop told him "good work!"
But the young man thought he was a jerk.
"How can cops death so light,
While I'm here frozen in fright?"
The young man thought.
"How is this good, because to me, it's not."
To kill the man is what he had to do,
To save his life, but if you were him, would you?