Dead Rising/Transmissionary

To get this achievement simply answer and listen to all the calls that Otis gives you on the walkie talkie during the entire 72-hour mission. You will need to go through most of the 72 hour mode doing the cases for you to receive all Otis's calls.

5 Survivors are needed also to complete this quest, Ronald Shiner, Floyd Sanders, Kindell Johnson, Cheryl Jones, Paul Carson, and Simone Ravendark. The details are in the survivors section.