Minnesota trophy hunter Walter Palmer is being severely judged in the court of public opinion, but he appears unlikely to face prosecution in the U.S.

American hunters stalking prey in foreign countries are subject to very few U.S. laws, said Anna Frostic, senior attorney for wildlife litigation at the Humane Society of the United States.

The African lion is not listed as threatened under the Endangered Species Act, the key U.S. wildlife statute. The U.S. Fish and Wildlife Service is considering adding the species to the list and faces an October deadline for that decision.

If the lions were added to the list, they would be subject to strict import regulations, which would probably freeze American interest in those hunts, Frostic said. “There would be zero incentive for U.S. trophy hunters to go over to Africa if they couldn’t bring their prize home.”

African lions are protected under part of a global treaty called the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES). It protects animals that aren’t currently threatened with extinction but that could be, in the absence of trade controls. The convention covers about 21,000 species.

Frostic said Palmer’s case might be covered by the Lacey Act, a federal law that prohibits trading in animals that are sold or taken in violation of national or foreign law. The act has been used to prosecute illegal trafficking in a wide range of items such as shark fins, ivory, turtles and rhino horns.

The Lacey Act could apply where an illegal hunt produced a body that was imported into the U.S. or sold in foreign commerce.

However, Frostic noted that according to Zimbabwe news reports, the lion’s head — the trophy — was impounded, and so the law might not apply.

A third American law covers U.S. citizens overseas, the Foreign Corrupt Practices Act. The anti-bribery law can apply if bribes are used during a hunt, but there have been no allegations of bribery in the Palmer case. Palmer appears to have paid a legitimate customary fee for the lion hunt.

A spokeswoman for the U.S. Fish and Wildlife Service said it’s too early to speculate about legal action.

The agency issued a statement saying it is “gathering facts” about the killing and will assist officials in Zimbabwe if requested.

A Justice Department spokesman said the Fish and Wildlife Service is taking the lead on the matter.

The U.S. has an extradition treaty with Zimbabwe, but the Justice Department won’t comment on extradition-related matters or whether a foreign country has made a request in a particular case.