The Postville meatpacking plant raided last month by federal immigration agents has hired a former federal prosecutor to monitor its compliance with the law, a company spokesman announced Thursday.

Jim Martin, a former U.S. attorney for the Eastern District of Missouri, will serve as the company's corporate compliance officer starting immediately, according to the statement from Agriprocessors Inc. Martin heads the Prevene Group, a St. Louis firm that advises companies on how to avoid legal violations.

"Retaining Jim and his team is part of an ongoing effort to improve compliance and safety performance," said Heshy Rubashkin, the plant's vice president. "We take responsibility to our employees, to Postville and to the observant community very seriously."

Martin said the plant's 800 jobs are "important to Postville and northern Iowa, along with the observant Jewish community across the country that relies on them for meat and poultry."

"Agriprocessors can meet the needs of those who depend on the company and operate in compliance with all laws," he said, "and I intend to see that happen."

Martin investigated white-collar and corporate fraud cases during his 21-year stint as a prosecutor, according to his biography on the Prevene Group's Web site. He recently was recognized in "Best Lawyers in America" for corporate governance and compliance law.

The new hire came less than a month after agents stormed the kosher plant in what was later deemed the largest single-site raid in U.S. history. Nearly 400 illegal immigrant workers were arrested in the May 12 operation, and 305 were charged with immigration-related felonies.

The bust also exposed allegations of physical and verbal abuse by the plant's managers, though none have been charged. The company also is interviewing candidates for a new chief executive officer.

The announcement came as U.S. Rep. Bruce Braley, an Iowa Democrat, criticized an Iowa Department of Labor Services decision to trim earlier fines against the plant by about 75 percent.

The fines originally totaled $182,000 for 39 safety violations, but were later cut to $42,750.

Dave Neil, the state labor commissioner, said Thursday in a letter to Braley that the agreement was designed to encourage Agriprocessors to fix the violations quickly. A drawn-out legal battle could have prolonged the unsafe conditions, he said.

Braley, in a response letter, said he understood the department's decision to reduce the fines and urged the department's "vigorous oversight" of Agriprocessors in the future.

"However, Agriprocessors presents a unique situation," Braley wrote. "This employer has a long and questionable workplace safety record. Recent public statements by the owner of Agriprocessors show a disregard for worker safety and enforcement of the law. In this case, I don't believe that drastically reducing the fines to Agriprocessors sends the right message either to the public or to this employer."