What did you make of the murder in the end? Why did the film end that way?

In death, Lester finally figures out what he never quite understood in life: that happiness is found in freedom, yes, but also in the love that you give and receive. True happiness is the ability to look at a fallen bird, or a paper bag dancing in the wind, and see its true beauty. Happiness comes from seeing the beauty in everything, from knowing that no matter how bad life seems, the world is a wondrous place. Through this realization, the film suggests that American beauty is democratic, far-reaching: there is indeed beauty everywhere you look, so long as you take the time to see.