The companies have, in many cases, investigated the claims and fired contractors.
Of 500 cases investigated by her unit each year, only about 100 result in prosecutions.
Mr. Vignola is also overseeing a review of previous cases investigated by Ms. Smith.
There were arrests in 96% of the murder cases investigated in 1995.
In about half the cases investigated, the staff found, the officers involved had failed to file a written record of the encounter.
In 93percentt of the 1,242 cases investigated by the Occupational Safety and Health Administration, the agency declined to seek prosecution.
The current commissioner, Mr. Okaili, said that only 396 of 15,000 cases investigated by the commission from 2005 through 2008 were prosecuted.
The five instances in which the Koran was mishandled, General Hood said, were among 13 cases investigated in the past two weeks.
In the 1952 fiscal year alone there were 156 convictions in bank robbery cases investigated by the FBI.
Mr. Ahmad has been the defendant in five cases investigated by the department involving allegations of fraud and predatory lending.
The cases, investigated by numerous government agencies including the F.B.I., the Internal Revenue Service, immigration and customs enforcement agencies, and the local police, were discussed at separate press conferences on Friday, one here and one in Los Angeles.
