Belgian media reported Monday morning that the gunman who killed four people in an attack Saturday at the Brussels Jewish Museum carried out the act while wearing a portable video camera on his chest.

If true, the behavior would be reminiscent of that of Mohammed Merah, who filmed himself killing four people at the Ozar Hatorah school in Toulouse, March 2012.

“Sources involved in the investigation” informed several news sites that while reviewing one of the museum’s security videos, it was observed that the suspect was bearing a GoPro brand camera that may have documented the event.

Belgian police on Sunday released video footage of the gunman entering the building, taking a Kalashnikov automatic rifle from a bag and opening fire on his victims — an Israeli couple, a French woman and a young Belgian man.

A second video showed the man walking outside the museum.

“We call on the whole population to help identify this person,” deputy prosecutor Ine Van Wymersch said.

She said the gunman “probably acted alone, was armed and well prepared.”

Belgium launched a nationwide manhunt Sunday for the lone suspect in the shooting spree.

Forensic experts examine the site of a shooting at the Jewish museum in Brussels, Saturday, May 24, 2014.  (Photo credit: AP/Yves Logghe)

Forensic experts examine the site of a shooting at the Jewish museum in Brussels, Saturday, May 24, 2014. (Photo credit: AP/Yves Logghe)

Interior Minister Joelle Milquet said that the shooter had parked a car outside before entering the Jewish Museum in the swanky Sablon area of antique dealers, hip cafes and museums, “fired rather quickly, went outside and left.”

The museum said in a statement that the gunman came in, started shooting at the tourist couple at the entry, “and then went on to the reception where he shot the attendant.”

Police had detained one suspect late Saturday but he was soon released and is now considered a witness.

Mira and Emanuel Riva, the Israeli couple killed in the terror attack on the Brussels Jewish Museum on May 24 (photo credit: Courtesy)

Mira and Emanuel Riva, the Israeli couple killed in the terror attack on the Brussels Jewish Museum on May 24 (photo credit: Courtesy)

The attack, which came on the eve of national and European Parliament elections, led officials to immediately raise anti-terror measures and protection of Jewish sites.

Van Wymersch said “all options are still open” regarding a motive for the shooting spree. But the government has said it had the hallmarks of an anti-Semitic attack. No one has claimed responsibility for the killings.

AFP and AP contributed to this report.