Just so you know, Jack Webb made a Dragnet TV movie in 1966. NBC was so pleased that they asked for a new half-hour series as well. The film was held back when the premiere of the series was pushed forward, not airing until 1969. Since then it has surfaced occasionally on cable TV but it is otherwise unavailable. Many fans consider it one of the best Dragnet works and hope that it may someday be released on DVD.
It was based on the case of Harvey Murray Glatman.
www.youtube.com/watch?v=61Wr5Vh-c8o
Or"
www.youtube.com/watch?v=ybhNquay6Sk
I don't know how they are different, but, there you are.