While a handful of horses are purposely sold into slaughter by irresponsible owners, most arrive at the slaughterhouse via livestock auction, where unsuspecting owners sell the animals to slaughterhouse middlemen known as "killer buyers." Despite the fact that the US plants are no longer in operation, killer buyers continue to purchase and haul as many horses as possible from livestock auctions around the country to the slaughterhouses that have now relocated to Mexico and Canada.