For those interested in the Nightstalker franchise, I recommend THE NIGHT STALKER COMPANION by Mark Dawidziak. It gives a lot of information on the tv movies and the tv series.
A few bits of trivia:
THE NIGHT STALKER tv movie was the most-watched tv movie in history when it premiered (the record was later broken by ROOTS).
Jeff Rice, who created Carl Kolchak, died penniless.
David Chase wrote a lot of the tv episodes. He hired Robert Zemeckis and Bob Gale for their "Chopper" episode (headless motorcycle rider) which was their first job. Zemeckis and Gale later became famous for writing BACK TO THE FUTURE. Chase later became famous for creating THE SOPRANOS.
Jack Grinnage played Ron Updyke, Kolchak's uptight co-worker at INS. Grinnage later became a prop maker and one of his props was the bullet-carrying rabbit's foot that John Malkovich used in Clint Eastwood's IN THE LINE OF FIRE.
The tv series was released on dvd a long time ago, but will be released on bluray, too.