"A Killer on the Loose: The Zodiac Ciphers" gives an extensive history of the Zodiac Killer and the attempts of the officials at Vallejo at capturing him. I believe that the producers were successful in making a good podcast and kept a balance between the content and the theatrical aspects of it.
The title itself gives the impression of an interesting podcast and serves as a good hook for the audience. Additionally, the background music complements the eerie tone set by the podcast and betters the experience of the audience. The structure of the podcast is such that it seems like an interesting story but is also filled with information and facts which seems like a good way of sharing raw information without causing much boredom. To refer to an example, the segment about cracking the Zodiac cipher seemed to come right out of a dramatic movie but was filled with precise information on the cryptanalytical steps taken.
Finally, I also felt that the conclusion was done in manner that inspired the audience to look up the focus of the podcast. By mentioning different unlikely theories, the producer was able to spark an interest in the different theories behind the identity of the Zodiac Killer. All these factors contributed in making this podcast a good production.