Not every police officer is eager to use lethal force, but too many are. Lethal force is only to be used when absolutely necessary. Putting an asthmatic father of six -- Eric Garner -- in a chokehold (which police aren't even supposed to do) for breaking up a fight, then justifying it by saying that he was "selling untaxed cigarettes" is not a necessary use of lethal force. Shooting a small dog through a closed car window because the officer "fears for his safety" is not a necessary use if lethal force.
The police face incredibly stressful situations every day, and when people are stressed, and feel threatened they are more likely to act irrationally and lash out with disproportional force. Letting all police carry guns is a recipe for disaster and heart break, and other methods of defence should be taught in it's place. Yes the police are too quick to use lethal force, but we give them the tools to make it so easy.
Where force is used, the police involved should have a formal investigation to decide if the decision to use force was justified or not. There are many reported cases of police brutality, but not many actions taken against the officers who abused their power. Police officers are humans, and just as able to commit violent crimes as any normal person, but can do so and call it the 'law'.
No, police are not too eager to use lethal force, because they are trained on when force is needed and when to use it. For every civilian that they kill, many officers are also killed in the line of duty because they do not use force enough. Mostly, it is a balanced use for force.
I do not think Police are eager to use lethal force. I think that although sometimes they use force when might not be needed or take too many shots in this case that they are isolated incidents. I think that you hear about these cases but you also don't hear about all the cases that they could have used it and didn't.