Former New York Mayor Rudy Giuliani on Wednesday said he would be in favor of forcing Muslims on the federal government’s terrorism watch list to wear electronic monitoring tags or bracelets for authorities to track their whereabouts.

“I would think that’s an excellent idea,” said Giuliani. “If you’re on the terror watch list, I should you know you’re on the terror watch list. You’re on there for a reason.”

Giuliani, who is advising the Trump campaign on terrorism and national security issues, told NJ Advance Media he would recommend that Trump undertake the same measures being used in France if he’s elected.

One of two suspects who murdered a priest during an attack on a Catholic church in Normandy Tuesday morning was wearing just such a monitoring device during the attack. He was known to anti-terror authorities to have twice attempted a trip to Syria because he was wearing it.