The end of the parsha deals with the sugya of a dead body found between cities and the offering of eglah arufah by the B"D as a kaparah. The leaders of the closest city must declare יָדֵ֗ינוּ לֹ֤א שָֽׁפְכוּ֙ אֶת־הַדָּ֣ם הַזֶּ֔ה וְעֵינֵ֖ינוּ לֹ֥א רָאֽוּ, that they are not guilty of spilling the blood of the victim. Do we really suspect the leaders of the city or the B"D of committing the crime?
Three approaches:
1) Rashi comments: וכי עלתא על לב שזקני בית דין שופכי דמים הם? אלא, לא ראינוהו ופטרנוהו בלא מזונות ולוייה. Of course we do not suspect that the leaders of the city are literally guilty of murder. However, they are perhaps guilty of letting someone pass through their city and not be given a welcome, not be offered any accomodation, not be given a proper escort upon departure, and as a result of their indifference, that lonely individual fell prey to criminals.
Chasam Sofer writes that in this context וְעֵינֵ֖ינוּ לֹ֥א רָאֽוּ is not meant as an excuse -- we didn't see anything, so we cannot be held accountable. Aderaba, it is part of what the leaders are asking kapara for. וְעֵינֵ֖ינוּ לֹ֥א רָאֽוּ, we were blind to what which we should have been attentive to!
2) The Yerushalmi (Sota 43), however, explains that the B"D is not suspect of indifference towards the victim, but rather of indifference towards the criminal. רבנין דהכא פתרין קרייא בהורג שלא בא על ידינו ופטרנוהו ולא הרגנוהו ולא ראינוהו והנחנוהו ועימעמנו על דינו. The leaders of the city must declare that they have not been lax in meting out justice; they did not catch the criminal and then let him go because they supported bail reform. Seforno comments: שלא הנחנו שום נודע לרוצח בארץ.
According to Ylmi, the responsibility placed upon the kohanim b'nei levi to carry out the eglah arufah because וְעַל־פִּיהֶ֥ם יִהְיֶ֖ה כׇּל־רִ֥יב וְכׇל־נָֽגַע is meduyak -- since they were responsibile for enforcing the law and failed, they are at fault. According to the other meforshim, it is harder to make sense of this phrase.
Netziv points out a nafka minah between these views. It's the closest city that has a B"D who must bring the eglah arufah. What kind of B"D must the city have? Rashi, l'shitaso of the Bavli, learns a B"D of 3 is sufficient. The Rambam, however, follows the Ylmi and learns that we measure to the closest city with a B"D of 23, because it takes 23 to judge dinei nefashos. Only that type of B"D can be held accontable for letting the killer off the hook.
Sadly in our society we all know of cases where Rabbis have not taking certain accusations as seriously as they should have, or have directed the accused to seek therapy instead of turning them over to the police to face the jail time they deserve, etc. But without going that far, there is indifference to murder of a different sort, that may not call for a B"D of 23 to judge, but nonetheless falls under the umbrella of the moral teaching not to turn a blind eye to crime. Rabeinu Yonah (S.T. 3:139) calls being malbin pnei chaveiro b'rabim "avak shefichus damim," murder with a lowecase m instead of a capital M, if you will. This is the lesson of Kamtza and Bar Kamtza, where the Rabbis who were sitting at that celebrating ducked for cover rather than stand up for Bar Kamtza.
According to the Ylmi, the close of the parsha makes a nice bookend to its opening. Shoftim v'shotrim -- we must establish a working justice system. And if we fail and let criminals off the hook, the end result is eglah arufah.
3) Lastly, Ibn Ezra suggests that ועינינו לא ראו – ויתכן, שהשם צוה לעשות כן העיר הקרובה, כי לולי שעשו עבירה כדומה לה, לא נזדמן אדם שיהרג קרוב מהם. ומחשבות השם עמקו וגבהו לאין קץ אצלנו. Those who live in the closest city must be guilty of some similar crime otherwise this type of outrage would not happen on their doorstep.
At the end of the eglah arufah ceremony, the kohanim declare כַּפֵּר֩ לְעַמְּךָ֨ יִשְׂרָאֵ֤ל אֲשֶׁר־פָּדִ֙יתָ֙ ה׳ וְאַל־תִּתֵּן֙ דָּ֣ם נָקִ֔י בְּקֶ֖רֶב עַמְּךָ֣ יִשְׂרָאֵ֑ל וְנִכַּפֵּ֥ר לָהֶ֖ם הַדָּֽם׃. Chazal darshen כפר לעמך – אלו החיים, אשר פדית – אלו המתים, מלמד שהמתים צריכים כפרה, נמצינו למדין, ששופך דמים חוטא עד יציאת מצרי. This unsolved murder requires kaparah not just from those currently living in the cities, but kaparah is required for generations past as well.
R' Leib Chasam points out that we don't find a similar statement in Chazal or a similar pasuk regarding an actual murder. You would think that if a whole ceremony is required to ask kaparah for generations and generations of Klal Yisrael when a body is found and we don't know the facts of the case -- we don't know who the victim is, we don't know if anyone who lived close by is really at fault in a direct way, we don't even know if the victim or criminal was Jewish -- kal v'chomer if we catch an actual murdered in our midst, how much more of a kaparah is required! How much more should be concerned that if such a thing happens on our doorstep, as Ibn Ezra writes, it must reveal that there is something rotten in our midst. So why does the Torah never say such a thing?
The answer he gives fits perfectly with the lesson of eglah arufah. It's not the crime per se that the the B"D comes to ask kaparah for, but it's their indifference which led to the crime, either indifference to the victim, indifference to the criminal, indifference towards other crimes in the midst of their city. When an actual murder takes place and it makes the front page news (though these days it's so common it doesn't even make the front page anymore), people take notice. People wonder what's going on, what do we need to do to stop the crime wave, people ask how such a thing could happen. When it's a no name victim somewhere on the outskirts of town, when it's easy to dismiss what happened as not our problem, not directly related to us, then we ignore it. The indifference is perpetuated. Therefore, the Torah requires an eglah arufah to make us take notice.