It’s been a tough week for Lisa Serna-Mayorga: The former aide to Mayor Kevin Johnson resigned shortly after city officials discovered $9,000 in personal expenses she loaded on a city credit card, and she now faces a criminal investigation. Serna-Mayorga has retreated into an Internet black hole, (ranSACked media.com notes that her Facebook page is gone, her LinkedIn account has been deactivated, and she’s not answering her phone) while city officials are left trying to sort out how the whole thing happened.

Ryan Lillis reports in The Sacramento Bee that Serna-Mayorga spent the money on a variety of personal expenses including gas, groceries and a trip to Disneyland while she was council operations manager for the city – a position she was appointed to by Johnson in 2008. She reimbursed the city for those expenses just before leaving her position as director of constituent affairs for the mayor’s district office.

Serna-Mayorga is the daughter of former Sacramento mayor Joe Serna, Jr., and the sister of current County Supervisor Phil Serna.

This isn’t the first time in recent memory that allegations of fraud and abuse have resulted in criminal investigations at City Hall. In 2010, city officials took some heat when development department employee Dan Waters (son of former City Councilman Robbie Waters) breached federal rules by giving permits to builders to develop an area of Natomas that the federal government had defined as a flood zone. That fiasco cost the city $350,000 in general fund dollars to correct violations of federal flood management laws. A subsequent audit of the development department found that the city lost $2.3 million in uncollected development fees in the three fiscal years leading up to and including the Waters situation.

Our capital city is not alone in city hall scandals. In recent memory, other California cities have faced similar problems, including the pensions abuse and financial misdeeds of city officials in Bell, and the payroll scandal in Vernon, where some city managers were making more than the governor.

But hey, however bad things get in Sacramento, at least we’re not Trenton, N.J.

The next step in the current drama is the pending criminal investigation of Serna-Mayorga to determine if her spending habits should result in formal criminal charges. According to the Bee, City Auditor Jorge Oseguera had planned an audit of all credit card use starting in September (save for the mayor and council members because of a conflict of interest).

Melissa Corker is a staff reporter for The Sacramento Press. Follow her on Facebook and on Twitter @MelissaCorker.