Authorities in Montana are searching for a killer who is "capable of truly heinous things" as they investigate the death of a man whose friend told police first he may have been the victim of a bear attack.

Investigators are asking for help solving a "vicious" murder in a remote camping in Montana that was so brutal a 911 caller had reported it as a possible bear attack.

"The caller indicated that the death may have been caused by a bear attack," the news release said. Start the day smarter. Get all the news you need in your inbox each morning. Multiple agencies,