"According to all of the witness accounts we've gathered ... (El Khazzani) wouldn't have hesitated to use all the arms in his possession -- assault rifle, pistol and box-cutter -- if it wasn't for the remarkable intervention of the passengers," Molins told reporters at a news conference Tuesday.

The 25-year-old Moroccan has been charged with attempted murder, attempted mass murder and membership in a terrorist organization, the prosecutor said -- because the gunman allegedly wanted to kill all the passengers on the train.

Crime investigators look into the window of the train.

Crime investigators look into the window of the train.

Police in protective suits stand on a platform next to the train.

Police in protective suits stand on a platform next to the train.

Police work on a platform next to a high-speed train in Arras, France, on Friday, August 21.

Police work on a platform next to a high-speed train in Arras, France, on Friday, August 21.

The high-speed train was zipping from Amsterdam to Paris when a shirtless man emerged from the bathroom -- a rifle slung over his shoulder, witnesses said. A French passenger and three Americans -- a civilian, an Air Force member and a National Guard member -- jumped into action. They quickly tackled him, possibly averting a massacre aboard the train. This frame grab image shows the bound suspect.

The high-speed train was zipping from Amsterdam to Paris when a shirtless man emerged from the bathroom -- a rifle slung over his shoulder, witnesses said. A French passenger and three Americans -- a civilian, an Air Force member and a National Guard member -- jumped into action. They quickly tackled him, possibly averting a massacre aboard the train. This frame grab image shows the bound suspect.

An undated photo released by a social network shows the 25-year-old Moroccan suspect in Friday's shooting, named as Ayoub El Khazzani. He lived in (southern) Spain in Algeciras for a year, until 2014, then he decided to move to France. Once in France he went to Syria, then returned to France, according to a Spanish anti-terror source.

An undated photo released by a social network shows the 25-year-old Moroccan suspect in Friday's shooting, named as Ayoub El Khazzani. He lived in (southern) Spain in Algeciras for a year, until 2014, then he decided to move to France. Once in France he went to Syria, then returned to France, according to a Spanish anti-terror source.

From left: Anthony Sadler, from Pittsburg, California, Alek Skarlatos from Roseburg, Oregon, and British national Chris Norman -- who is living in France -- hold medals they received for stopping a gunman on a European train.

From left: Anthony Sadler, from Pittsburg, California, Alek Skarlatos from Roseburg, Oregon, and British national Chris Norman -- who is living in France -- hold medals they received for stopping a gunman on a European train.

Spencer Stone, one of the passengers who overpowered the gunman who had an assault rifle on a high-speed train, gestures as he leaves the hospital of Lesquin, northern France, on Saturday, August 22. On August 21, a gunman opened fire on the train traveling from Amsterdam to Paris, injuring two people before being tackled by several passengers. Stone, an off-duty member of the U.S. Air Force, was first to the gunman, who slashed him in the neck and almost sliced off his thumb with a box utter.

Spencer Stone, one of the passengers who overpowered the gunman who had an assault rifle on a high-speed train, gestures as he leaves the hospital of Lesquin, northern France, on Saturday, August 22. On August 21, a gunman opened fire on the train traveling from Amsterdam to Paris, injuring two people before being tackled by several passengers. Stone, an off-duty member of the U.S. Air Force, was first to the gunman, who slashed him in the neck and almost sliced off his thumb with a box utter.

Molins said El Khazzani has invoked his right to remain silent after days of "evasive answers."

Before he assembled his weapon in the toilet compartment between two train cars on Friday, El Khazzani sat on the train -- bound for Paris from Amsterdam -- listening on his phone to a YouTube file of "an individual calling his followers to combat and urging them to take up arms in the name of the Prophet," Molins said, saying this was indication of his terrorist intent.

After bursting out of the bathroom with his assault rifle, El Khazzani was met by a French man who was waiting there and who tried to stop him. El Khazzani fired off several rounds, and the man escaped through the doors into the next car, the prosecutor said.

From left: Anthony Sadler, Spencer Stone, Alek Skarlatos and U.S. ambassador to France Jane Hartley pose after a press conference at the U.S. Embassy in Paris on August 23, 2015.

El Khazzani then went into one of the cars, where two American servicemen jumped on him when his weapon jammed and -- with the help of another American and a British man -- managed to bring him down and tie him up, Molins said.

Did suspect have support?

As the investigation into the thwarted attack and the suspect continues, authorities are looking into a key question: Was the suspected gunman a lone wolf or did he have support?

Molins said that authorities are trying to pinpoint where the alleged gunman got the weapons he had and how he got the money to buy a first-class ticket.

"We will try and determine where he got these weapons, where he has been in Europe, anybody who has worked with him and his source of financing," Molins said.

According to the French prosecutor, El Khazzani has maintained that he found the weapons in a park. He told investigators during interrogations that he intended to rob train passengers and then escape through a window.

Authorities said El Khazzani was recently in Hatay Province in southeastern Turkey, close to the Syrian border. On June 4, he traveled back through Istanbul to Albania -- a side destination that he may have used to cover his tracks.

El Khazzani's defense attorney, Sophie David, told CNN affiliate BFMTV and other media organizations that her client denies he is a terrorist.

"The suggestion makes him almost laugh," she said.

El Khazzani wanted to carry out an armed robbery, she said, and did not intend to spark a terror alert.

Wife recalls harrowing moments before shooting

When she heard her husband's voice, passenger Isabelle Risacher Moogalian knew the situation was dire.

"Get out. This is serious," he warned her.

"I looked at his face, and I knew he was not kidding, because he looked very intense," she told CNN in an exclusive television interview Tuesday.

Moments later, she was crouching behind a seat on the train while her husband -- French-American academic Mark Moogalian -- tried to take away the gunman's rifle. She heard at least one gunshot go off, then watched her husband in horror from a few seats away.

"He fell to the ground. ... My husband thought he was going to shoot him again, so he played dead," she said.

Now Mark Moogalian is hospitalized with a gunshot wound. His condition worsened overnight at a hospital in Lille, in northwestern France, but he was starting to feel better on Tuesday, his family said.

Authorities have said he will be awarded the French Legion of Honor once he recovers.

Four other passengers who stopped the gunman received the Legion of Honor from President Francois Hollande on Monday.

One of them, Briton Chris Norman, told CNN that he preferred to die trying to stop the man, rather than sitting and waiting for a near-certain death.

"My position was, I'm not going to be the guy who dies sitting down," Chris Norman told CNN's "New Day." "If you're going to die, try to do something about it."

'The power of the citizens'

Norman said that he and Hollande had a conversation at the award ceremony in which they discussed the importance of everyone participating in the fight against terrorism.

Police cannot be everywhere, Norman said.

"I think as citizens, we need to really move forward and we need to take some of the responsibility for it," he said, referring to the battle against terrorism. "Whether it is simply being more vigilant or by preparing yourself for action if ever you do find yourself in that situation.

"I'm not an expert in the area but I do think we need to figure out how to harness the power of the citizens," he said.

Norman told CNN's Chris Cuomo that he and the others who subdued the apparent would-be attacker, though they had never met, acted as a team during the takedown.

He has had a chance since Sunday to talk with the others -- Anthony Sadler, Spencer Stone and Alek Skarlatos , three American friends on vacation in Europe -- about those critical events.

"I think we've got a pretty strong bond," he said.