Debris from a crashed Airbus A320 is seen in the mountains, near Seyne-les-Alpes, France, on March 24, 2015, in this still image taken from TV. The Airbus operated by Lufthansa's Germanwings budget airline crashed into a mountainside, killing all 150 people on board. Reuters via Reuters TV/Pool

Questions about the religious background of Andreas Lubitz, the Germanwings pilot who investigators said deliberately crashed a plane in the French Alps this week, killing all on board, have sparked outrage and debate about whether such information is relevant to the investigation. When a reporter asked French Prosecutor Brice Robin of Marseille, during a news conference Thursday, whether he knew Lubitz’s religion, Robin said he did not know and added, “I don’t think that’s where the answer to this lies.”

The question suggested that Lubitz’s religious background was relevant to the investigation behind the pilot’s alleged deliberate downing of Germanwings Flight 9525 on Tuesday. Robin said the crash did not show any signs of terrorism. Some were appalled by the reporter’s inquiry.

“This line of questioning makes no sense to me whatsoever,” said Elizabeth Shakman Hurd, an associate professor of political science with a courtesy appointment in religious studies at Northwestern University in Illinois. “I find it disturbing and depressing that at a time like this some people feel compelled to search desperately for explanations that presume religious causation.”

Religion has come into question in past plane incidents. In 1999, the pilot of a Boeing 767 intentionally plunged the fully loaded plane into the Atlantic Ocean 30 minutes after takeoff from New York City on a nonstop flight to Cairo. An investigation found the pilot, Gamal al-Batouti, had said several times in Arabic, “I rely on God,” as the plane's autopilot function was disconnected and Egypt Air 999 plunged. The phrase is often associated with the moments before death.

The U.S. National Transportation Safety Board concluded that no mechanical event could have caused the plane to dive. But Egyptian officials never accepted the conclusion that al-Batouti had intentionally crashed, and conspiracy theories spread.

It's unclear what role Lubitz's faith will play in the Germanwings investigation. “Jumping to conclusions does not help ease the pain for the families who are mourning a horrific loss. It also does not help the investigators do their jobs,” said Corey Saylor, a spokesman for the Council on American-Islamic Relations, a Muslim civil rights advocacy organization based in Washington.

People on social media Thursday criticized the reporter for bringing up Lubitz's religion, arguing that he would be considered a terrorist only if it was revealed he was Muslim.

The reporter’s question also prompted others to ask about the 28-year-old pilot’s religion and ethnicity. Some on social media jumped to the conclusion that Lubitz was Muslim.