I have long argued that Israel’s policy toward convicted terrorists is a tragically misplaced mercy.In the nearly 70 years of its existence, the State of Israel’s civil court system has never ordered the execution of those convicted of capital crimes. There was of course one famous exception. After his apprehension by the Mossad in Argentina, Israel executed Adolph Eichmann, one of the chief architects of the Holocaust, on May 31, 1962. Aside from this monster Israel has allowed a nearly incalculable number of murderers to escape a similar fate.To name just a few examples: Abu-Musa Salam Ali Atia murdered 67-year-old Holocaust survivor Isaac Rotenberg, a man whose entire family was exterminated at the Sobibor death camp, by repeatedly striking at his neck with an ax Raai Ibrahim Salam Ali axed another 79-year-old Holocaust survivor to death as he read a book on a park bench.Tsalah Ibrahim Ahmed Mugdad beat a 72-year-old hotel worker to death with a steel rod.Sha’at Aazat Shaba’an Aataf was an accomplice in the murder of Simcha Levi, a Jewish woman who spent her days transporting Palestinian day laborers to work in Jewish settlements in the Gaza Strip – until being beaten to death by her very passengers.Abu-Sitta Ahmed Sayid Aladin and Abu-Sitta Taleb Mohammed Ayman murdered David Dadi and Haim Weizman, even cutting off their victims’ ears as proof of the killing.All of these men, and thousands of others, were all tracked down, arrested, tried and convicted by the State of Israel. They could not escape the long, heavy hand of justice. Until they did.With the death penalty abolished, Israel allowed all of these murderers, and thousands of others, to live. Worse, Israel freed these men, along with 1,021 other murderers, in exchange for the kidnapped Gilad Schalit – a crime which was itself committed with the express intent of wresting murderers from Israeli prisons.The prisoner swap, just one of a series of such exchanges in the past decades, allowed over one thousand unrepentant murderers – men who beat, stabbed and shot their helpless victims – to be granted a new birth of freedom.I will never forget how Hamas and the Palestinian Authority ululated and celebrated the return to their society of a thousand murderers who had taken the lives of so many innocent men, women and children in Israel. Israel will be forever haunted by the horror-infused festivities that followed the prisoner release.Now again, after the horrific recent murders in Halamish, the issue of capital punishment has once again come to the fore of Israeli public debate.On a warm Friday night last month, 19-year-old Omar Abed walked three kilometers from his home with a Koran, a water-bottle and a knife. After jumping a protective fence, the young man entered at random the home of the Saloman family, stabbing to death a father and his two children as they sat around their Shabbat table celebrating the birth of a grandchild. After being shot by an alert neighbor, the attacker feigned death in order to attack the rescue workers when they arrived to help revive him – another attempt at murder in which he was thankfully less successful.A few years ago, I visited the Fogel home, where yet another terrible massacre took place. I went up to the window from which the terrorists escaped. They were later caught and after initially denying their involvement in the massacre they later bragged about it. They are currently serving life sentences in Israeli prisons, but as with all terrorists in Israel, there exists the permanent possibility that they can be released at any moment in a prisoner exchange, making it so much more painful for families to heal.And now the butcher of Halamish will join them. He, too, will have within his heart the lingering hope that he will be released once Hamas kidnaps the next Israeli soldier and negotiates another lopsided prisoner exchange. He too will look forward to a chance at freedom that rests entirely within the realm of possibility.Or, perhaps, not.Israelis from all across the political spectrum have risen to whatever platforms they can to call for a capital trial and execution of the cold-blooded killer Omar Abed.According to a recent poll, 70% percent of Israelis now see capital punishment as the singular path fit for so cold-blooded a killer. Several Israeli politicians, including Defense Minister Avigdor Liberman and even MK Michael Oren, questioned the leniency of Israel’s court systems against senseless killers like Abed.Prime Minister Benjamin Netanyahu called for the death penalty to be finally invoked. During a meeting with the grieving family in the week after the killing, Netanyahu made his position perfectly clear: “My position as the prime minister is that in this case, with such a lowly murderer, he has to be executed. He should simply never smile again....”Any morally-minded individual with a commitment to justice ought to join their call for an end to the possibility of terrorists being released through a prisoner exchange.Like America with Timothy McVeigh, the Oklahoma bomber who murdered 158 and was executed in 2001, Israel should have a death penalty for terrorists.Terrorists must know – without a shadow of a doubt – that when they stab, ax and pummel innocent men, women and children to death they will never survive to celebrate their gruesome records in the streets of Gaza City.There are those who will argue that by refusing to execute convicted murderers, Israel has opted for a path that is more humane. After all, how, by killing those who kill, do we truly demote the act of killing? To that I answer that we are not calling for the killing of killers, we are calling for the killing of murderers. The Bible never says that one cannot kill. On the contrary, in the case of self-defense in a life-threatening situation, all ethicists agree that killing may be required. The prohibition, rather, is against murder. Murder is not just an act of killing. It is an act of killing the innocent – those who did not by any means deserve their deaths. Those who never received the most cursory of trials. Those who lived a life of peace and virtue, like the wholesome family of Halamish, yet were murdered with undisguised savagery.Repentance, too, cannot be a part of this equation. The capital cases of terrorism are not those of an individual caught up in the heat of rage, or who’ve succumbed to a sickness, or to a drunk and uncontrollable fury. These are not people who err, even gravely, and tearfully repent of their sins in court. These, rather, are individuals who carefully organize, plan and execute their evil plots. These are men who have lost their ability to see the humanity in their fellow man. These are people so steeped in their own hatred that it becomes an inextricable part of who they are.Timothy McVeigh was executed after a fair trial and an appeal with no public outcry whatsoever in the United States. A man who takes so many lives so coldly has erased the divine countenance from his visage. Why would Israel lock up the most rancid, heartless and cold-blooded killers in its jails just so that they can serve as a lure for more Gilad Schalits to be kidnapped to force their release? It would be logistically impossible to re-arrest the 1,027 murderers released in the Schalit deal and give them the sentences they truly deserve. It is also impossible to stop them from returning to bloodthirsty terrorism. But with the Halamish terrorist in custody, Israel ought to finally make the critical point, as summed up by the prime minister: those who bring endless grief to innocent families should smile no more.The author, “America’s rabbi,” whom The Washington Post calls “the most famous rabbi in America,” is founder of The World Values Network and is the international best-selling author of 31 books. Follow him on Twitter @RabbiShmuley.