An investigation into the misuse of credit cards at Sacramento City Hall culminated in the arrest Tuesday of Lisa Serna-Mayorga, a former aide to Mayor Kevin Johnson.

With bail set at $50,000, she was booked into the Sacramento County jail on various felony counts, including the misappropriation and grand theft of public funds. She was released late Tuesday.

"As I said when this issue came to light last summer, I am saddened by this news," Johnson said in a written statement. "The city moved swiftly to investigate and also conducted an audit of credit card use citywide. As charges have been filed, it would be inappropriate for me or my office to comment on any of the details. As the judicial process takes its course, our thoughts are with her family."

Serna-Mayorga, 40, is the daughter of the late Mayor Joe Serna Jr. and is the sister of Sacramento County Supervisor Phil Serna.

"I loved my sister before this incident, I love her now, and I will continue to do so as she deals with this," he said in a statement issued after her arrest.

The arrest followed a Sacramento Police Department investigation, requested in August by City Manager John Shirey, into possible criminal misconduct by Serna-Mayorga.

As council operations manager from December 2008 to July 2012, she served as office manager for the mayor and council's office. In that position, she was issued a Sacramento city bank purchasing card to be used solely for city business.

It is alleged that from July 2009 to June 2012, Serna-Mayorga used the card for personal items totaling more than $19,000, according to a news release on Serna-Mayorga's arrest issued by District Attorney Jan Scully.

Among the allegations of illegal charges were two Disneyland trips for Serna-Mayorga and her family in December 2010 and June 2012. The total amount of Disney-related purchases was $1,840.92, according to a summary of the police investigation released by the DA's Office.

Other charges were made for hotels in Bodega Bay and Monterey, clothing, makeup, restaurants, grocery bills and numerous iTunes games, music, movies and entertainment applications, according to the DA's summary.

Between Sept 20, 2011, and May 26, 2012, approximately 1,085 Apple iTunes purchases were attributed to Serna-Mayorga's iTunes accounts. Of those, 1,071 appeared to be personal in nature – games, music, movies and miscellaneous entertainment apps – according to an investigation summary. The purchases totaled $3,790.29.

Investigators reported that a number of purchases not related to city business were made on weekends or other days when Serna-Mayorga was scheduled to be off work.

In June, when an internal audit revealed that Serna-Mayorga had not been submitting required paperwork documenting her purchases, she admitted that numerous charges were personal, according to investigators. On June 28, she wrote two checks totaling $3,029.17 to reimburse the city for food and travel-related purchases. On July 18, she wrote another check to the city for $6,000 to cover additional personal expenses she had charged.

But, officials said, stop payments were placed on all three checks before the city could submit them for deposit. Furthermore, they said, Serna-Mayorga's checking account did not have sufficient funds to cover the checks.

Investigators found that the signature of the mayor's chief of staff, Kunal Merchant, was forged on some of the accounting documents Serna-Mayorga had submitted.

In addition to the misappropriation and grand theft of public funds, she is accused of forgery, and making or drawing worthless checks. If convicted, Serna-Mayorga could face a prison term of six years and eight months, according to the DA. She is scheduled to appear in court Dec. 26.

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