[Answer revised 10/18/10] - Dear Rich: How can I find out whether the Jack Webb audio of "you have the right to remain silent" is available in the public domain? I have been able to secure the Dragnet theme music in the public domain but haven't been able to discern whether his audio is still copyrighted. The piece I'm looking at using appears to have come from the original radio program. Some members of the Dear Rich staff almost broke into tears when they heard the Dragnet theme song. We're not sure why that is. Possibly it's a result of the atonal post-modern musical arrangement, or maybe because our tear ducts dried up on the bicycle ride through downtown Berkeley, or maybe it was a nostalgic gut punch reminding us of the good old days when beat cops didn't have to Mirandize every con they busted. Which brings up one issue: Are you sure the Jack Webb quote you have about "remaining silent" is from the 1950's radio show? Miranda warnings weren't required until 1966 although it's always possible that diligent police officers like Joe Friday were also concerned about Constitutional rights.
Public domain? According to a few sources on the Internet (like this one), the 1950s Dragnet radio programs are in the public domain. The radio programs would have two copyrights. The text copyright (covering the scripts) is likely to be in the public domain if the shows were never registered or renewed. (In any case, short phrases such as the Miranda warnings cannot be protected under copyright law.) The audio recording copyright is different because federal law did not protect audio performances until 1972. Pre-1972 audio is protected by a patchwork set of state or common law copyright rules. However, the prevalence of these shows on the Internet and for sale at Amazon seems to confirm that nobody is claiming or enforcing rights to Dragnet radio.
Are you sure about the theme song? Even if the radio shows are in the public domain, the theme is not, according to the attorney for the publisher, Dragnet Music Company. Apparently the copyright for the theme music -- also known by the title, "Danger Ahead," -- was renewed approximately 30 years ago. The composition was the subject of a lawsuit (the theme wasallegedly pilfered from the 1946 film The Killers) and it is currently listed as being owned by Dragnet Music Company. The attorney who contacted us explained that inquiries regarding commercial use requests are welcome and that unauthorized uses will be pursued.