The story is shocking yet so familiar. A Machias man pleaded guilty earlier this month to shooting and killing his ex-girlfriend in front of her three children and then shooting the woman’s male friend. The shooter, Richard Widdecombe Jr., 27, had once dated the woman, but she had ended the relationship five months earlier. Prosecutors said he had become obsessed with her after the break-up, sitting in his car outside her house for hours at a time, watching.

About half of Maine’s homicides each year are committed by current or former spouses or partners. Too many fit the profile of the spurned boyfriend or former husband who kills the woman who once was the love of his life, and sometimes her new lover, heeding the bizarre but powerful inner voice that says, “If I can’t have her, no one will.”

While women also are prone to violence when they are tossed aside or the victims of adultery, dozens of Maine homicides perpetrated by men in recent years are eerily similar to the Widdecombe scenario, suggesting this is very much a guy thing.

Though it risks stereotyping, it seems some men have problems processing the emotions that follow breakups. It may stem from an innate inability to express feelings, it may come from cultural taboos about venting sadness and loss, but too often, hurt turns to anger, and anger, to violence.

Renate Klein of the University of Maine’s College of Human Development and Family Studies, stresses that such men are in the minority of their gender. But the pattern of “leaping from hurt to anger” exists. Much of it, she believes, is culturally endowed. One “manly response” to a problem is expressing anger and rage, she said. For a man to acknowledge being hurt is to “signal vulnerability,” or weakness, Ms. Klein said.

One of Mr. Widdecombe’s foster mother described him as “the most abused child I have ever taken into my home.” His attorney, Jeffrey Davidson of East Machias, added that Mr. Widdecombe’s childhood “is the most horrendous story that I have ever read or ever known about.” The abuse began at birth, the attorney said: “Physical, sexual, you name it.”

This should remind policy-makers in Augusta and Washington that tough talk on crime and punishment is less than half the story; preventing such horrors before they manifest into damaged, dysfunctional adults is a moral imperative and fiscally prudent. In bad economies, domestic violence increases, and so may child abuse. There may be more of these cases in the coming years.

We can be thankful most boys avoid Mr. Widdecombe’s sad fate. And that makes him an aberration, not a trend. But again, finding the key to unlock why girls who are abused tend not to turn to violence when spurned while boys sometime do is a worthwhile inquiry.

Educators, counselors and those who study human behavior should work to rewire what seems to be a male short-circuit. And men themselves should work to become more reflective. The pain of rejection should not lead to anger and violence.