Lamondes D. Williams offered to help people rent apartments despite their poor credit.

Instead, he stole their money, leaving some of them without a place to call home.

For that, a Circuit Court judge in May convicted Williams, of Temple Hills, of felony theft and conspiracy to commit aggregate theft over $500. The judge also convicted him of running a pyramid promotional scheme. In all, Williams, 36, was convicted on 11 counts. Late last month, the judge sentenced Williams to five years in prison.

Francisco Sandoval hired immigrant day laborers to help build a four-story luxury condominium complex in Bowie, then stiffed them. In April, Sandoval pleaded guilty to seven misdemeanor counts of failing to pay wages. According to prosecutors, Sandoval, a subcontractor, agreed to work out a payment plan with the dozen workers whose labor he stole.

Both cases were prosecuted by the Prince George's state's attorney's rejuvenated Economic Crimes Unit -- or, as its three members call it, the fraud squad.

The unit had been quiet in the recent past, until it received a makeover a little more than a year ago at the direction of State's Attorney Glenn F. Ivey. He was concerned that theft and fraud cases were not getting the attention they deserved.

"I think it's critical to have the capability of aggressively prosecuting these kinds of crimes, and we do now," Ivey said.

The unit has successfully prosecuted dozens of cases affecting hundreds of victims who have been bilked, scammed or simply denied money they are owed.

Some examples, according to prosecutors:

* In January, a woman was convicted of embezzling $96,000 from a car dealership where she worked as an office manager. She was sentenced to two months in jail and five years probation, and ordered to repay what she stole.

* Between January and April, two men and a woman pleaded guilty to stealing checks from a U.S. Agriculture Department building and cashing them for a combined total of about $8,000. The three were ordered to pay restitution for the full amount.

* In January, a woman was convicted of embezzling more than $30,000 from the company where she worked as a bookkeeper. She was sentenced to six months in jail and ordered to repay all of the money.

The cases can be daunting.

During a complex, three-week trial, Prince George's prosecutors presented 350 exhibits and produced evidence in the Williams case showing that he had stolen more than $200,000 from at least 65 renters who had hired him.

Each of the unit's three prosecutors has a background helpful in going after white-collar crime: The chief, Isabel Mercedes Cumming, previously worked as an internal auditor at a bank; Assistant State's Attorney Doyle L. Niemann once owned his own communications and marketing business; and Jennifer Japp worked as an accountant for a large Washington developer before joining the state's attorney's office.

A Tough Reputation

A couple of news articles taped to Cumming's office door offer a glimpse of her aggressive style as a prosecutor -- and suggest why the Economic Crimes Unit is winning cases.

"Eight executed for fraud," says one headline on a story from the South China Morning Post, about a multimillion-dollar embezzlement. "WRATH OF ISABEL," says another that appeared in the Baltimore Sun.

Cumming, 43, was recruited by Ivey from the state's attorney's office in Baltimore in May 2004, when he began to revamp the Economic Crimes Unit. Ivey was looking for someone with a record of being tough. Cumming is widely thought to be one of Maryland's top prosecutors of white-collar crime. She recalled that Ivey's pitch was direct: He wanted to create the premier economic crimes prosecution unit in the state, and he wanted her to run it.

Cumming took the job and began working in the state's attorney's office last August, commuting to Upper Marlboro from the Towson home she shares with her husband and their two sons, skateboarder Joey, 7, and golfer Stephen, 9.

"I truly love going after white-collar criminals," said Cumming. "It's all I've ever done as a prosecutor."

Yet prosecuting criminals was not what Cumming set out to do.

She majored in accounting at James Madison University in Virginia, where she earned a bachelor's degree. She then earned an MBA at the University of Baltimore's Merrick School of Business. From 1984 to 1993, Cumming worked in Baltimore as a senior auditor for KPMG Peat Marwick and as an auditor for American National Bank. She enrolled in the University of Baltimore School of Law and took classes at night while working full time.

In 1993, she earned a law degree and began a 10-month, unpaid stint as a law clerk in the U.S. attorney's office in Baltimore. She fell in love with the idea of prosecuting fraud, and joined the state prosecutor's office. In 2000, she joined the Baltimore state's attorney's office.

Paybacks Are Satisfying

Cumming said she loves working in the county.

"There are a lot of schemes in Prince George's County. The level of sophistication here is higher than what I saw in Baltimore," she said of the cases that come before her. "Keeps my job interesting."

Cumming, Niemann and Japp currently are investigating or prosecuting more than 100 cases, including some involving embezzlement, identity theft and counterfeiting.

When she is not in court, Cumming often travels around the county, speaking to community groups about scams and how to avoid them, and whom to turn to for help if someone becomes a victim of a crime or scam. Some of the cases Cumming and her unit have prosecuted have come from people who attended one of her talks.

In almost all cases that end with a conviction or guilty plea, Cumming, Niemann and Japp have obtained orders for restitution for the person or business that was victimized.

Anyone convicted of an economic crime who is ordered to make restitution but fails to do so may be considered in violation of probation and tossed in jail.

Japp estimated that 70 percent of Prince George's defendants who are ordered to pay restitution do so. "After they're caught, they don't want to go to jail," said Japp, 42, who prosecuted the Williams rental scam case with Cumming.

Niemann, a Democratic state delegate from Prince George's, primarily prosecuted narcotics and juvenile cases before joining the Economic Crimes Unit.

Many theft and fraud victims are vulnerable, prosecutors said, such as the elderly and immigrants who are working-class or poor. Obtaining restitution for them is satisfying, said Niemann, who prosecuted Sandoval, the subcontractor who admitted to not paying the day laborers.

"It was an example of using the power that we have to help people who would otherwise not be helped," Niemann said.

That power works both ways, prosecutors said.

Take one recent case: A woman Niemann successfully prosecuted on a theft charge last spring was nearing the end of her six-month jail sentence when her 8-year-old son was killed in a traffic accident.

An attorney for the woman asked the judge if the woman could be let out of jail to attend her son's funeral. The judge referred the attorney to the Sheriff's Office, which said she could attend if escorted by a sheriff's deputy.

Cumming and Niemann consented to a motion by the woman's attorney to allow the woman to attend the funeral without an escort.

"It was the right thing to do," Cumming said. "As a mother, to not be able to say goodbye to your son would be the most horrific punishment."

Bruce V. Marcus, the woman's attorney, said, "I was truly impressed by the show of humanity and compassion by Mr. Niemann and Ms. Cumming, who were able to put aside the adversarial nature underlying the legal proceedings to help someone in need."

Prosecutor Isabel Mercedes Cumming, right, talks with LaVonda Moates about the sentence for Lamondes D. Williams. Cervantes Davis, above, and, at left, Rena Jones, left, LaVonda Moates and Stacey Harewood were among the more than 60 people victimized in a rental scam run by Williams.