The New York Times reports: He stabbed an off-duty police officer and left him bleeding to death on his own doorstep. He forced his way inside the home and stabbed and killed the officer’s female companion. He then sat down and videotaped himself live on Facebook declaring allegiance to the Islamic State, according to the French law enforcement authorities.

Sitting just behind him was the couple’s son, a terrified 3-year-old boy, of whom Larossi Abballa, the killer, said dismissively, “I have not decided what to do with him,” according to David Thomson, a French journalist for Radio France Internationale and the author of a book on jihadists who saw Mr. Abballa’s online posts before they were taken down.

The events that unfolded between about 8 p.m. and midnight on Monday — when elite police forces broke into the house in the small town of Magnanville, fatally shot Mr. Abballa, 25, and rescued the boy — were the second time within 48 hours in which a person appearing to act alone claimed to kill in the name of the Islamic State.

In the attacks in both Magnanville and Orlando, Fla., the killers had more than just brushed up against the authorities before, in what has become a distressingly familiar pattern — from the set of attacks in Paris in November, to those in Brussels in March and beyond. The Orlando gunman, Omar Mateen, had been interviewed twice by the Federal Bureau of Investigation for his possible links to terrorism, and Mr. Abballa had been convicted for having links to a terrorist network and served about two years in jail before being released.

Further complicating the job of protecting Western nations are governments’ dual goal of preserving civil liberties while trying to make people feel secure.

The attack in France was shocking not only to neighbors in Magnanville, about 35 miles from Paris, but across the country because it underscored that extremist attacks can happen in the most ordinary places, above all in those where people believe they are safe.

Mr. Abballa’s Facebook post from Monday night made clear that he wanted to terrify and destroy those he deemed “unbelievers,” people he had come to hate. He also wanted to encourage other lone wolves to do the same.

“It’s super simple,” he said, looking into the camera. “It’s enough to wait for them in front of their offices; don’t give them any respite. Know this, whether you are a policeman or a journalist, you will never feel calm again. One will wait for you in front of your homes. This is what you have earned.”

Boasting that he had “just killed a policeman and I just killed his wife,” he called on fellow believers to give priority to killing “police, prison guards, journalists.” He specifically named several writers and journalists, adding rappers to the list because, he said, they “are the allies of Satan.”

Even more chillingly, he warned that jihadists had “reserved some other surprises for the Euro; I am not going to say more.’’

“The Euro will be a cemetery,” he said, referring to the Euro 2016 soccer tournament being played over the next several weeks in 10 French cities.

It was unclear whether Mr. Abballa had specific knowledge of a potential attack on the matches or the crowds gathered for them.

The version of the video released by the Islamic State’s Amaq news agency was trimmed by a couple of minutes to omit images of the boy and Mr. Abballa’s references to him. On Twitter, opinion was divided between those who thought the images of a defenseless child were tasteless even by the standards of the Islamic State’s hardened propagandists and those who speculated that the extremist news agency did not want to show Mr. Abballa as unwilling to kill a child. [Continue reading…]