The board of the National Rifle Association (NRA) is facing pressure to suspend the gun rights group’s chief executive, Douglas Hamlin, following revelations that Hamlin was involved in the sadistic killing of a cat. The news broke as Donald Trump cancelled a planned appearance with Hamlin next week in Savannah, Georgia, where the Republican nominee for president was meant to give a keynote address to an NRA convention. Organizers said Trump had a scheduling conflict. An anonymous letter sent by “concerned employees” of the NRA to the board contained a litany of concerns about Hamlin, who was appointed in July following a corruption scandal at the group. Chief among those concerns was new revelations – published by the Guardian last week – that Hamlin was involved in the gruesome killing of a house cat named BK when he was the president of his fraternity at the University of Michigan in Ann Arbor in 1979. “Anyone who can do that and try to cover it up is a sadistic human and cannot be trusted with the organization’s reputation and employees’ safety,” the letter said. The employees added: “If something is not done, Doug Hamlin will destroy any chances of a NRA comeback.” The letter was first reported by the Daily Mail. Hamlin pleaded no contest to an animal cruelty misdemeanor and he and four of his fraternity brothers were expelled from the fraternity. The cat was captured, had its paws cut off, and was set on fire, according to local media reports at the time. Hamlin released a statement to some outlets saying he did not condone the actions that took place more than 44 years ago. “I took responsibility for this regrettable incident as chapter president although I wasn’t directly involved. Since that time I served my country, raised a family, volunteered in my community, started a business, worked with Gold Star families, and raised millions of dollars for charity. I’ve endeavored to live my life in a manner beyond reproach,” he said. The NRA did not respond to a request for comment.