It was arrogance that drove the former managing partner of what was one of the state’s largest accounting firms to carry out elaborate schemes to steal more than $500,000 from his own company, the prosecutor said Monday in opening statements of the trial of Patrick Oki.

Oki, 47, a certified public accountant and certified fraud examiner, is on trial in state court on 13 counts of theft, money laundering, forgery and using a computer to commit the theft and money laundering. The computer charges are the most serious and carry mandatory penalties of 20 years in prison.

The charges accuse Oki of stealing $503,897 between January 2011 and January 2014 when he was managing partner of PKF Pacific Hawaii LLP. In October 2015 new partners who joined the firm after the alleged theft executed a buyout agreement with Oki and later changed the company’s name to Spire Hawaii LLP.

Deputy Prosecutor Chris Van Marter said Monday that Oki “engaged in a pattern and practice of cooking the books so that they would appear however he needed them to appear to further his criminal scheme.”

Van Marter said Oki created fictitious companies and employees with their own websites and email addresses, phony correspondence, contracts, invoices and tax forms. He said Oki doctored a hotel receipt to appear as though an employee of one of the fictitious companies he created had stayed at the Trump International Hotel and Tower in Waikiki when in fact it was his girlfriend who stayed in the hotel.

In one of the schemes, Van Marter said, Oki told his partners that two of the phony companies were doing business with the CIA. He said the other schemes revolve around the phony purchase of Hawaiian Cement by a Japanese company.

In each scheme, Oki told his partners that he was using his money to pay clients’ expenses, which in turn the firm needed to reimburse, and that the clients would later refund the company, Van Marter said. He said Oki also transferred money from his company credit card to his PayPal and Square online payment accounts, then transferred the money again into his own bank account.

Van Marter said that because none of the phony clients made any payments, at one point PKF was unable to cover all of the reimbursements Oki requested. So instead, the PKF partners reduced by $60,000 the amount Oki owed the company for an earlier loan.

Oki’s lawyers did not make an opening statement Monday. Oki waived his right to a jury trial.

Circuit Judge Rom Trader will decide whether Oki is guilty of any crimes.