A former U.S. soldier known as Rambo who became a mercenary for drug dealers has been sentenced to life in prison by a judge who cited his "truly horrific crimes."

Joseph Hunter, a onetime sergeant from Kentucky with a Special Forces background, was sentenced Thursday by U.S. District Judge Ronnie Abrams in Manhattan.

She said he carried out his crimes, including arranging the 2012 murder of a real estate agent in the Philippines, for money. The life prison sentence was mandatory. Hunter, listed with the alias "Rambo" in an indictment, is serving a 20-year prison term after another conviction.

Prosecutors say Hunter tortured, kidnapped and killed people for years along with other former soldiers.

The judge says she was struck by the matter-of-fact manner in which they killed.