People accused of shooting endangered species are getting off the hook thanks to a U.S. Justice Department policy that some federal wildlife officials say amounts to a loophole in the Endangered Species Act. Adopted in 1998 under the Clinton administration, the policy requires government prosecutors to prove that a suspect knew the animal they were killing was endangered. “We have to show a mental state, which for federal agents is very difficult,” said Neill Hartman of the U.S. Fish and Wildlife Service. The policy has hampered dozens of federal criminal prosecutions in cases where grizzlies, wolves, lynx, condors, and other endangered animals have been killed. “If you don’t prosecute, who’s to stop someone from going out and taking a bear just because they want a grizzly in their trophy room?” asks Hartman. Wildlife officials have asked the Bush administration to change the policy, but to no avail.