IOWA CITY — Prosecutors have dropped trespassing charges against an activist who helped secretly record Iowa’s largest pork producer using heat to kill thousands of hogs last year as the pandemic devastated the industry.Matt Johnson, an activist with the group Direct Action Everywhere, had been scheduled to stand trial in Grundy County on Monday on two counts of trespassing at Iowa Select Farms properties in May.County prosecutors moved to dismiss the charges Thursday at the request of Iowa Select, whose personnel had been subpoenaed but said they didn’t wish to testify, court documents show.“We cannot be distracted by individuals who choose to break the law and grandstand,” Iowa Select spokeswoman Jen Sorenson said Friday.Johnson was planning a necessity defense, arguing that his actions were lawful because they were the only way to expose the inhumane treatment of animals.