Kansas City, Mo. ? A former Kansas City pharmacist who diluted chemotherapy medications and other drugs has asked a federal judge for an eight-month reduction in his 30-year sentence.

Robert Courtney was sentenced in 2002 after pleading guilty to diluting drugs for seriously ill patients and keeping the money for himself. Prosecutors have said 4,200 patients and about 98,000 prescriptions were affected.

In a motion he filed without legal help, Robert Courtney argued that U.S. District Judge Ortrie Smith misunderstood how federal prisons calculate time off for good behavior, which generally is 15 percent of a total sentence.