Goodbye mansions, hello jail: Nevada woman stole $26 million from construction boss — then the IRS caught up with her

Goodbye mansions, hello jail: Nevada woman stole $26 million from construction boss — then the IRS caught up with her

Laura Boast

Thu, August 6, 2026 at 1:00 PM GMT+3 4 min read

For seven years, Las Vegas-area couple Cynthia Marie Marabella and her partner William Keolanui Costa were living the dream: mansions, fast cars, expensive clothing and merchandise.

But then the IRS Criminal Investigation (IRS-CI) unit started asking questions. Like how Marabella, a controller at a Las Vegas construction company, could amass millions of dollars. By February 2025, the dream was over.

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In April of this year, Marabella and Costa, both of Henderson, Nevada, each pleaded guilty to one count of wire fraud and one count of monetary transactions in criminally derived property.

In July, a District of Nevada court sentenced Marabella, 46, to five years and 10 months in prison for embezzling more than $26 million from her employer. The court also ordered her to repay all the money.

Her partner Costa, 42, a security company owner, faces up to 30 years in prison. He will be sentenced Sept. 2. As Las Vegas media outlet KLAS reports, the case is connected to Costa's February 2025 kidnapping of Larry Gilmore, owner of Gilmore Construction LLC, where Marabella worked.

Here's how the couple colluded to steal millions — and how the law caught up with them.

Financial controller engages in fraud, boyfriend kidnaps her boss

Marabella had access to money and financial statements in her role at Gilmore Construction. She was in charge of accounts payable and receivable as well as bank and credit card statements.

She and Costa copied bonus checks and deposited the fraudulent checks into their own bank accounts. They opened credit cards in other people's names and racked up charges on them, repaying the charges with the embezzled cash.

According to the DOJ, the couple used the money they stole to live like millionaires in mansions, drive around in luxury cars and buy expensive merchandise, which Marabella then sold online through a consignment company, thereby laundering the money.

Marabella covered up her tracks at work by faking accounting records, bank statements and merchant invoices. The couple carried out the scheme from Jan. 1, 2018 to Feb. 28, 2025.

But by late 2024, the IRS-CI and the Henderson Police Department had uncovered the extent of the fraud, and alerted the construction company owner, Larry Gilmore, of the embezzlement.

As KLAS reports, not long after, in February 2025, Costa kidnapped Gilmore and threatened him with regards to the case. Gilmore reported the incident to the police. Costa was arrested the next day. This year, on Feb. 9, Costa pleaded guilty to one count of first-degree kidnapping and one count of extortion.

Scott Brown, Acting Special Agent in Charge of the IRS CI Phoenix Field Office, said the scale of such crime inflicts "deep and lasting harm on victims and their families."

"The fallout reverberates throughout the entire business, impacting everyone who depends on it for their livelihood," he said in a press release.

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Embezzlement is one of the most common workplace crimes

The Association of Certified Fraud Examiners (ACFE) reports that embezzlement and cash theft represent 90% of workplace frauds, with an average loss of more than $1.4 million. The median scheme goes undetected for a year due to poor internal controls, with employee tipoffs being one of the most common detection methods.

Marabella is not the only controller to take advantage of her boss. According to the Controllers Council, 77% of workplace frauds take place in just eight departments — with the top three being accounting, operations and sales.

The Controllers Council says if money is going missing from the company till, look out for employees:

• Living beyond their means (like Marabella), 41% of the cases

• Struggling with financial challenges, 29% of cases

• A very close relationship with a supplier or customer, 20% of cases

• Problems letting go of control or sharing duties, 15% of cases

• Dealing with family problems, 14% of cases

As the council says, "If the books look a bit light, it's always a good idea to look towards the people in charge of them."

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This article originally appeared on Moneywise.com under the title: Goodbye mansions, hello jail: Nevada woman stole $26 million from construction boss — then the IRS caught up with her

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