When a body is found close to a city, mistama if the murderer was a member of the nearest city, he would be discovered by the police and apprehended. The eglah arufah scenario is a crime from out of the blue, with no clue as to who the culprit is. The zekeinin declare, "Yadeinu lo shafchu es ha'dam ha'zeh," -- "We know none of the people in our town did this -- so why is this on our doorstep?" Things don't just "happen" for no reason -- there must be something wrong that would ellicit Hashem sending such a tremendously disturbing wake up call. The pasuk is not a declaration of innocence, but rather of guilt.
Chasam Sofer adds an explanation of the end of the pasuk, "V'eineynu lo ra'u." The zekeinim are responsible for the oversight of their town. When inexplicable tragedy occurs, it means they have been remiss in their job, they have failed to see wrongdoing that they should have been aware of, and therefore, their failure to act has led to tragedy.
When terrible things happen, we hope and pray that they murderer is not from our community, our town (and as we know from the tragedy that happened in the summer, we can't even be sure these days that the murderer is in fact not living right under our noses). But that doesn't mean we aren't guilty. To ever hear of such tragedies, to have them happen in our own backyard, is a sign that something is rotten in Denmark.
I want to add two points. Most of us will hopefully never have to be part of an eglah arufah investigation -- we won't find a body lying on the doorstep -- but that doesn't mean the parsha doesn't apply to us. Ani chashuv k'meis -- Chazal tell us that a poor person is considered like someone who is dead. Thanks to the times we live in there is not one, but dozens of meisim out there that can be found and "no noda mi hikahu," no one knows what happened to cause such a situation. We need to ask why did this happen in our community, on our watch? What is the wake up call telling us? What did we fail to see that needs correcting?
And lastly, I would like to suggest derech derush a slightly different reading of the end of the pasuk, which, even if you don't like it, at least give me originality points. B'pashtus, "Yadeinu lo shafchu..." is a protestation of innocence. "We didn't spill innocent blood." I read "V'eineynu lo ra'u" the same way, with a little twist -- not, "We did not see anything wrong," but rather, "Our seeing did not cause anything wrong." What do I mean? Think of how cheap life must become for a murder to occur. How can such a thing happen? Easy. Think of how many murders and killings occur in a month of TV programs that you can just sit back and watch as if it is sport. Think of how many times you can shoot and kill the other guy in some online game. Newspapers every day now have full color pages so you can actually see the rishus described, not just be satisfied with a word filled description. When all this is in front of your eyes day in and day out, is it any wonder that an eglah arufah can happen?! The Torah is telling us that you can't feign shock and declare innocence unless you can honestly say, "eineynu lo ra'u," we have not created an environment when such things are absorbed by our eyes. If our eyes take in everything out there, then eventually it doesn't just penetrate our eyes, but it penetrates our minds and from there it penetrates our actions and attitudes.