Moogalian, 51, is a professor at the University of Paris and was traveling from Amsterdam with his wife, Isabelle
Credit: Jacqueline Moogalian Pittman

Mark Moogalian, the 51-year-old French-American professor identified Monday as the heroic passenger who grabbed the AK-47 weapon away from the gunman aboard a European train on Friday, did “what was right in his heart” and “saved so many,” according to his sister.

“It’s like he was put there [on that train] to stop this horrific massacre,” Mark’s sister, Jacqueline Moogalian Pittman, tells PEOPLE.

“He’s just Mark, he did what came to him instinctively,” she says. “He went into protective mode. It was great. His good human nature kicked in. He was raised by good parents.”

Moogalian, who was shot in the back after wrestling the AK-47 away from the shooter, is the fourth man authorities say helped to take down the gunman, identified as 25-year-old Ayoub El-Khazzani. USAF Airman First Class Spencer Stone, Army National Guard Specialist Aleksander “Alek” Skarlatos and Anthony Sadler eventually subdued the gunman and saved Moogalian’s life by suppressing his gunshot wounds. A fifth man wishes to remain anonymous.

. Moogalian Pittman, of Douglasville, Georgia, says that her brother and his wife, Isabelle, would often travel to Amsterdam from Paris on vacation. Mark moved to Paris 25 years ago to pursue a career as a musician and is currently a professor at the University of Paris.

“He’s a strong-willed guy. He would give the shirt off his back to anybody. He’s just a kind guy,” she says. “He did not think when he grabbed that AK-47, he was just protecting his wife and people on the train. He would be embarrassed that we are talking about this right now!”

Mark, a protective husband, allegedly told his wife to hide behind a seat, telling her to “get down, get down,” when he realized what was going on.

“He told her this was serious and to get behind the chair, as she watched what happened,” says Moogalian Pittman, 54. “That was all he could do, was put her behind the seat and pray that she wouldn’t be seen.

“They are a lovely couple,” she adds. “He is a beautiful human being inside and out, he loved her and was protective of her, of course.”

A close family member, who wishes to remain anonymous, tells PEOPLE that Mark “thought the [gunman’s] briefcase was suspicious” when he first boarded the train and “him and another gentleman in the back of the train asked what was in it.”

The gunman then went into the train’s bathroom, near the back of the high-speed vehicle, where the exits were.

When the shooter came out, he was carrying an AK-47.

According to the same family member, in an attempted altercation to subdue the shooter, Mark bravely grabbed the rifle from the man and started running, but he was shot in the back with a different weapon.

The bullet “went through [Mark’s] lungs and out his neck.”

“I’m not surprised he did this, that’s his personality,” says the family member. “He’s very patriotic, he’s very upfront about his thoughts. He doesn’t like people to bully people. He’s not going to consider himself a hero, but this doesn’t surprise me at all. He’s always helping people. He should receive the highest honor medal for France!”

On Monday, the three Americans were presented with the Légion d’Honneur, France’s highest award, for their roles in stopping the gunman’s attempted terrorist attack.

Mark is still in the hospital, according to his sister, awaiting further treatments and surgeries.

He is expected to be honored once he is well enough.