An internal investigation at the Federal Bureau of Investigation has found that the agency mishandled, mislabeled, and lost evidence in every region of the country. The agency is also storing more weapons, two tons more drugs, and less money and valuables than its records indicate. The report was based on a review of more than 41,000 pieces of evidence in FBI offices and could affect future criminal investigations, since lawyers are able to get evidence thrown out of court because of record-keeping discrepancies. Most of the mistakes appear to come from the FBI’s transition to a computer system called Sentinel. But some of the errors include disappearing evidence, which is more serious. “A majority of the errors identified were due in large part to human error, attributable to a lack of training and program management oversight,” auditors wrote in the report.