Hawzah News Agency (Strasboug, France) - The interview with Abdelkrim Chekatt by the state-run France 2 television channel was shown last night, two days after the son was killed in a confrontation with three police officers in his childhood neighborhood in Strasbourg following a massive manhunt.
Four people died in the attack. A dozen others were wounded.
The Christmas market in the eastern city of Strasbourg, seat of the European Parliament, is the largest in France.
It reopened on yesterday after being closed during the search for the suspect.
Chekatt said he had seen his son, Cherif Chekatt, three days before the attack but couldn't contact him while he was on the run.
He acknowledged that his son backed the IS group.
"He'd say, for example, that Daesh, fights for the just cause and all that," the red-bearded father said, using the common term in France and elsewhere for the Islamic State group.
The interview, initially outdoors with the father, continued briefly inside with Cheriff Chekatt's mother, Rouadja Rouag, who expressed shock and sorrow for the deaths.
France 2 said the couple had been divorced for a long time.
Abdelkrim Chekatt, a French-Algerian, said he'd tried in the past to dissuade his son from backing the Daesh, saying, "You don't see the atrocities they commit." The son would reply that "it's not them," the father said.
Shortly after Chekatt's death, the Islamic State group's Amaq news agency claimed he was a "soldier" of the group. French Interior Minister Christophe Castaner rejected the claim as "totally opportunistic."