He was engaged at what he almost certainly thought of at the time as a holy endeavor, removing temptations to idolatry.

“Extremist Pleads Guilty in Hague Court to Destroying Cultural Sites in Timbuktu,” by Marlise Simons, New York Times, August 22, 2016:

PARIS — An Islamic extremist pleaded guilty on Monday at the International Criminal Court to destroying shrines and damaging a mosque in the ancient city of Timbuktu, Mali, in the court’s first prosecution of the destruction of cultural heritage as a war crime.

Prosecutors said that Ahmad al-Faqi al-Mahdi, a member of a jihadist group linked to Al Qaeda, took part in the smashing of a number of venerable centuries-old mud and stone buildings holding the tombs of holy men and scholars.

Mr. Mahdi, a teacher who was born in or around 1975 near Timbuktu and who studied Islamic law in a Saudi-sponsored school in Libya, was also accused of leading a “morality brigade” that meted out punishments like public floggings for minor infractions.

“It is with deep regret and great pain that I had to enter a guilty plea on all the charges brought against me,” Mr. Mahdi told the court on Monday. Begging for forgiveness, including from the people of Timbuktu, he said, “I would like them to look at me like a son that has lost his way, and to accept my regrets.”

Mr. Mahdi added that he was “influenced by a group of deviant people from Al Qaeda and Ansar Dine,” a Qaeda offshoot in Mali, and said that he hoped his punishment would “serve as a purging of the evil spirits I got involved with.”

He faces a maximum sentence of 30 years in prison, but prosecutors will request a sentence of nine to 11 years as part of a plea agreement.

Fatou Bensouda, the court’s chief prosecutor, said that it was Mr. Mahdi “who identified the sites to be destroyed and who provided the means” to do so, including pickaxes and crowbars….