Well busting down the door would help, because they can get to the owner, before the owner could be killed. Why does he think the owner will be killed? And cop's are suppose to announce their presence in a situation like that, so the owner knows that it's the police and not some intruder. So isn't it okay for the officer to announce his presence? I read that that is what they are suppose to do, when entering a house to protect someone. See above.
And yes normally a single officer will not enter, but this particular character, is compelled to not let the owner die because of his character, so is compelled not to wait for back up, if the owner is in immediate danger, and he can see it in the windows. How can he see someone is in immediate danger? How does he think going in himself is going to save someone and not make it worse?
But if the cop can see an intruder with a mask and a gun, through the dark window, by shining a light on the window, World's dumbest cop. and the owner is in another room, is that not enough to enter? It is for him, since he is that type of character. What type of character? Dopey and ill-trained?
Now he could go all the way around to the back entrance of the house, where the intruder entered, but that would take more time. He feels he has to get in immediately, so if he doesn't have time to go all the way around to the back to where the back door was broken into, wouldn't he try to get in the front some way? WHY is this his plan, and if he hasn't even walked around the whole house, he's even dumber.
As for firing door breaching rounds into the locks, door breaching rounds are specifically designed to break into metal powder and not go through the other side of the door. They bust locks only and if someone else one the other side, the person will not be hit, or so the round is designed for. So after announcing that he is the police and to move, could he fire through the door then legally? He's run out of his car, shined a light through the front windows, said he's the cops and now magically has those rounds on him, knows the formation of the door, magically, and does this?
Plus I was told by a cop before, that the police have to announce their presence when going into someone's house to stop an intruder, so wouldn't he?