Security footage shows the man responsible for one of the Philippine capital's deadliest attacks in years casually exiting a taxi just after midnight and walking calmly into a vast entertainment and gambling complex like any other visitor.

READ more: IS not behind casino attack

Shortly afterward, he dons a black ski mask, slips on an ammunition vest and pulls an M4 carbine assault rifle out of his backpack.

What follows borders on the surreal: a slow-motion arson attack and robbery so methodical and unhurried, the gunman appears to walk much of the way - even as he exchanges fire with a security guard and flees, slightly wounded, up a stairwell.

The Islamic State group claimed responsibility for the early Friday rampage at the Resorts World Manila complex. At least 37 patrons and employees died, mostly from smoke inhalation as they tried to hide, while the gunman fled to an adjoining hotel and reportedly killed himself.

The video footage shown to reporters Saturday, though, bolsters the government's case that this was a botched robbery by a lone attacker with no known link to terrorism. Police said that's exactly why they wanted to release it.

In his first remarks on the assault, President Rodrigo Duterte said that the attacker was simply "crazy." He questioned what the gunman was going to do with the $2 million horde of poker chips he had tried to haul away. He also discounted any links to the Islamic State group, saying this "is not the work of ISIS. The work of the ISIS is more cruel and brutal."

Despite some initially contradictory accounts of the chaos, what is known so far appears to back up that claim.

Although the attacker was well armed -- Manila police chief Oscar Albayalde said he was carrying 90 bullets in three rifle clips -- there are no confirmed reports that he shot any civilians. Instead, he fired into the ceilings, scattering panicked crowds, some of whom jumped out windows to escape what they believed to be a terror attack.

Albayalde said the security footage also indicated a clear motive. The gunman headed straight for a storage room in the back of the casino that contained poker chips. He is seen shooting through several thick white doors, breaking down one of them at 12:18 a.m. Friday -- only 11 minutes after his arrival.

More than 12,000 people were in the complex at the time; most were successfully evacuated.

"He could have shot everybody there," Albayalde added. "He could have killed hundreds of people inside that establishment. But he did not shoot anybody … he just burned the casino. Burning the casino could be a diversionary tactic for his escape."

By nightfall Saturday, the gunman's identity was still unknown. The taxi driver who dropped him off told police  his passenger spoke fluent Tagalog and appeared normal during the ride. The gunman asked him just one thing: to change the radio channel to the news instead of music, Albayalde said.

"All indications… point to a criminal act by an apparently emotionally disturbed individual," said Presidential Spokesman Ernesto Abella.

Philippine National Police Chief Ronald dela Rosa also said the attack did not appear to be terrorism, but he cautioned that authorities still know very little about the attacker.

"What if we establish the identity and there are leads that will lead toward terrorism? So our findings, our conclusion, will possibly change," he told DZMM radio.

The Philippines has faced Muslim insurgencies for decades, though much of the violence has occurred in the troubled south. Many in Manila feared Friday's attack was linked to ongoing battles with militants aligned with the Islamic State group in the southern Philippine city of Marawi. The fighting has placed the country on edge and prompted Duterte to declare martial law across the south.

IS carried two statements claiming responsibility for the attack, but they contained discrepancies. One mentioned fighters, the other just one fighter -- a person who goes by the nom de guerre "Brother Abu al-Kheir al-Arkhabili." One of the statements also said the attacker "died as a martyr" -- which would not make sense if he shot himself in an evacuated hotel room at the end of the night, as the police claim. Suicide is forbidden in Islam.

Armeen Gomez, chief security officer at Resorts World, said witnesses at the scene had testified to seeing multiple assailants. But he believes their accounts were likely confused by the chaos and panic. Beyond the unidentified gunman, the only other people armed in the images released Saturday were the security forces clearing the area.

The footage shows the attacker entering an elevator with two women behind him, shortly after arrival. He pulls a mask down across his face as he walks out, and minutes later, he strolls into a part of the mall with round dining tables, bypassing the metal detector.

As a security officer runs after him, he whips a rifle out of his backpack, sending panicked throngs fleeing. This was the moment people began screaming, "ISIS! ISIS!" Gomez said.

Pushing deeper into the complex, the gunman enters the casino zone. A shocked man behind a counter ducks as the attacker fires into the air. He then begins dousing gambling tables and slot machines, igniting each with a lighter.

Luchie Arguelles, 61, was playing slots just after midnight when she saw the man enter. "(He was) all dressed in black, burly, everything was covered, you can't even see his eyes," said Arguelles, who was about 9 meters (30 feet) away. She said he was holding two small bottles.

"I said, 'He's going to burn that table, he's going to douse it,'" before she grabbed her husband's hand and started running.

In the footage's last scenes, the gunman is seen exchanging fire with one of the hotel's security officers at a stairwell doorway. Gomez said the gunman was shot in the leg, but after walking up a couple steps, the assailant walks back down to casually shut the door -- almost as if he had left it open by mistake.

Later on the fifth floor, he sets part of a red hallway carpet ablaze, filling the corridor with smoke. Hotel security had already evacuated guests.

At 1:46am, the gunman kicks in the door of Room 501 and goes inside. Police soon arrive, aiming the white lights on their weapons through the smoke-filled hall.

The attacker, they say, set a final fire in the room and was found dead with a gunshot wound to the mouth.