Brodhead police are asking the public’s help in finding the source of materials used to make methamphetamine found by a resident Thursday night. Authorities say a homeowner in the 500 block of 14th Street found the materials in a shopping bag near a shed and brought them to the police department. The items were used to make methamphetamine through a process called the one-pot method. The method involves mixing chemicals in plastic bottles to make the drug. Police warn the mixture can be extremely volatile.