Charges will not be filed against a 93-year-old Acton man who was arrested on suspicion of illegally manufacturing PCP, the district attorney's office said. There was insufficient evidence linking Walter Todd to a makeshift drug laboratory discovered in a trailer behind his house, Deputy Dist. Atty. Steve Cooley said. Todd was arrested after Los Angeles County sheriff's deputies responded to citizens' complaints of a strong, pungent odor and found traces of ether and chemicals used to manufacture PCP in the trailer. But detectives could find no evidence that Todd, described by neighbors as "frail" and "cantankerous," was aware of what was happening in his trailer, Cooley said.