A former D.C. public schools official, who ran a student transportation business on the side, admitted Wednesday that he billed the city for $300,000 worth of rides that were never provided.

Donnie Dukes, who worked as a compliance officer, pleaded guilty to overbilling the city agency responsible for busing students with disabilities. He enticed D.C. school system employees to help carry out his scheme by giving them concert tickets and access to vacation properties, according to the plea agreement Dukes signed.

The charges against Dukes, who previously worked as principal of Options Public Charter School, come amid a separate criminal probe involving Options that is linked to a civil case alleging improprieties by three school managers. Dukes’s plea agreement, which includes a cooperation provision, suggests that he is helping federal investigators in their criminal examination of Options.

The allegations against Options became public in October when the D.C. attorney general alleged in the civil lawsuit that leaders of the Northeast Washington school for at-risk teenagers had diverted more than $3 million to for-profit companies they founded.

No one has been criminally charged in the Options case, but it is the subject of a federal grand jury inquiry, according to people with knowledge of the case.

Dukes’s attorney Brian K. McDaniel told U.S. District Judge Ketanji Brown Jackson on Wednesday that his client has “provided information” to federal prosecutors. He declined to elaborate on Dukes’s cooperation after the hearing.

“It’s a difficult day for Mr. Dukes,” McDaniel said. “He’s looking forward to putting the matter behind him.”

After working at Options, court papers say, Dukes became a compliance officer for the District’s public school system in 2008. He was responsible for arranging transportation for ­special-needs students who receive educational services outside D.C.

For two years, Dukes urged colleagues to refer special-needs students to Joyce Ann Thomas Children’s Services, a business he owned and named after his mother. Dukes hid his ownership from co-workers, according to the plea agreement. Through that scheme he illegally obtained $163,621, court papers say.

When Dukes’s position with the school system was terminated in 2010 because of budget cutbacks, he planned to use profits from the transportation business to open a for-profit charter school in the District, according to court documents.

But Dukes no longer had access to the school system’s nonpublic list of students in need of transportation, court papers say. “To overcome this hurdle, Dukes provided things of value to his former colleagues at DCPS,” including concert tickets and meals, according to the statement of offense.

In April 2011, for instance, a former Office of the State Superintendent of Education (OSSE) employee e-mailed Dukes a list of students and he was “able once again to target students for transport.”

When Dukes did not raise the money he needed to open a charter school through legitimate billing, he began creating phony documentation. He faked 60 invoices, billing the city $300,000 for services that were never provided, according to court documents.

The District’s inspector general and attorney general began looking into the payments in September 2011, after OSSE received information that the company’s invoices were padded. Two months later, a schools worker who handled billing was fired. She has not been charged with wrongdoing.

A spokeswoman for OSSE declined to answer questions about Dukes and the OSSE employee who aided his scheme, citing ongoing legal proceedings.

“Since the incident, OSSE has implemented a number of policies and procedures strengthening the payment process to prevent abuse,” spokeswoman Ayan Islam said.

According to Dukes’s plea agreement, he faces jail time ranging from 27 to 33 months on wire-fraud and conflict-of-interest charges. Dukes also agreed to pay restitution of $463,621.

The judge agreed to delay sentencing until June 17 to allow Dukes to finish the school year at Parkdale High School in Prince George’s County, where he said he works. Prince George’s school officials said they were looking into his employment status.

Ovetta Wiggins contributed to this report.

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