In a press conference, national capital region police office Chief Director Oscar Albayalde identified the attacker as Jessie Carlos, 43, a Filipino and a resident of Santa Cruz district in Manila.
Relatives of the gunman approached the police early Sunday and positively identified him, said Albayalde.
Carlos was an employee of the Philippine's Department of Finance who was dismissed from service in April, 2014 for grave misconduct and gross neglect of duty and for failure to declare properties and a business interest in his statement of assets and liabilities.
The attacker was also hooked in casino gambling and was heavily indebted, said Albayalde.
"He has a bank account with an outstanding debt of 4 million pesos ($81,000), and several other non-bank related debt," he added.
The gunman was banned by the Philippine Amusement and Gaming Corporation from all casinos upon the request of his family.
Armed with a rifle, Carlos opened fire and set ablaze the Resorts World Manila's casino early Friday which killed 37 guests and employees of the resort. He later doused his bed with gasoline and shot himself to death in the hotel room he retreated.
The Police chief said he was hoping the release of the gunman's identity would end speculations that the attack was the work of Daesh.
"On this note, we also reiterate our prior statements that this is not an act of terrorism but this incident is confined to the act of one man alone," Albayalde said.
