Mester Manufacturing Company makes furniture at facilities in San Diego, California. INS Agent Shanks made an educational visit to the facilities in July 1987. On September 2, 1987, INS agents inspected I-9s on file at the facility. The INS then made a computer search of its records, which showed that the numbers on the green cards used by three employees belonged to other aliens. On September 3, 1987, Shanks gave Barry Mester, the company president, a handwritten list identifying the three employees in question. Mester took no investigative or corrective actions. On September 25, INS agents returned to again inspect Mester's I-9s and found that the three named individuals suspected of using false green cards were still employed by Mester. Mester was penalized a total of $1,500 for continuing to employ the three individuals. Mester appealed, contending that INS did not give it proper notice that it suspected green-card fraud and that the evidence did not support a finding of green-card fraud. Which party has the burden of proof? Decide. [Mester Manufacturing Co. v. INS, 879 F.2d 561 (9th Cir.)]