Does anyone know the title of a 70's sci-fi movie about a crashed ufo that had 3 aliens escape & kill people?

The 3 aliens escaped from a crashed spaceship and killed several people.One alien had poisonous fangs.The second alien could only be killed by the first alien's poison and the third alien would kill by draining life from it's victims. A stranger arrived in this small town and claimed to be a reporter,when in fact he was sent to investigate the crash. He turned out to be from the same planet where the pilot of the crashed spaceship came from.