Hawaii County Mayor Billy Kenoi’s assertion that he thought it was OK to spend taxpayers’ money on personal expenses such as a $1,200 surfboard and an $892 bill at a Honolulu hostess bar as long as he paid back the money does not withstand simple scrutiny.

Government prosecutors will decide whether Kenoi’s misdeeds rise to criminality, but it is already clear that the mayor has grossly violated the public trust and called into question his fitness to serve. Kenoi has needlessly and heedlessly squandered the confidence voters invested in him to serve with integrity.

The state and county policies outlining use of government-issued credit cards, known as pCards, are crystal clear in explaining that they are to be used only for official, authorized government business — not personal expenses. Not only are Hawaii County pCard users required to purchase only items necessary for their government work, they are supposed to seek the best value when doing so.

The rules are intended to prevent fraud, theft and abuse, a standard that must be met to reassure the taxpayers that elected officials and government employees are trustworthy stewards of public funds. Kenoi has failed to uphold this essential standard.

He signed a pCard user agreement confirming that he understood the requirements, which include: "I will not use the pCard, under any circumstances, for unauthorized personal use."

Yet, at least $22,000 worth of personal expenses are included among the roughly $123,000 worth of expenditures Kenoi charged on his pCard from January 2009 to March 2015, the Hawaii County newspaper West Hawaii Today reported.

The mayor repaid the county during that time period for personal items such as a $700 bill at a Hilo kara-oke bar and $566 in dues for the state bar association, the newspaper reported.

County officials said that personal spending was unauthorized and that Kenoi had been warned in the past.

Moreover, Kenoi paid back another $7,500 worth of charges and interest only last week, after his misuse of the pCard was exposed.

The county had rebuffed for years attempts to obtain Kenoi’s monthly pCard statements, documents now made public.

Given all these facts, the mayor’s assertion that he did not know what he was doing was wrong is utterly implausible.

His claim that he always meant to reimburse the taxpayers for unauthorized personal expenses also is suspect, given that such a large repayment came only after his spending patterns were exposed.

Kenoi has said that he exercised poor judgment and that his spending mistakes were entirely his own. However, state and county policies call for pCard charges to be vetted by someone other than the cardholder.

Random audits and other measures are supposed to be imposed to ensure compliance. Oversight necessary to protect the taxpayers’ interest clearly failed in this case, and investigators must find out why.

The Hawaii County prosecutor is evaluating the mayor’s case, and the state Attorney General’s Office is ready to assist, especially if conflicts of interest arise or if the investigation expands beyond the mayor’s office — as it should.

There are about 237 Hawaii County employees authorized to use pCards, among the several thousand county and state workers who are authorized users statewide. Accounting and oversight must be stringent and other misuse rooted out and halted.

State Attorney General Douglas Chin said that determining culpability in credit-card fraud cases often centers on the cardholder’s intent. Kenoi, a lawyer, insists that he did not intend to defraud the taxpayers. Only a vigorous and thorough investigation will determine the truth of that claim.

Chin has the public interest in mind in stepping up to ensure that this serious matter gets the attention it deserves.

The silence of so many members of the Hawaii County Council in the wake of Kenoi’s misconduct was discouraging; only Councilwoman Margaret Wille spoke up quickly to insist that the mayor is not above the law and should be held accountable.

Not only is Kenoi not above the law, but as the mayor, he should be held to the highest standard of ethical behavior. Mayor Billy Kenoi has admitted failing to uphold that standard, and his excuse for doing so simply does not ring true.