In September 2019, Gregory T. Monahan became acting chief of U.S. Park Police. He previously served as assistant chief in charge of the San Francisco field office, where he arranged for charges to be dropped against employees of the Presidio Trust, which funds the Park Police, after they assaulted officers. As a police officer, Monahan was investigated for wrongdoing in at least four instances for illegal body cavity searches. On multiple cases, Monahan's testimony was dismissed in court because the judge did not find him to be credible or truthful.