Here is a map of all the audio logs 1-29.
Audio Logs
Once you have all 29 you need to play Data Hive. When you advance to the part where you have to jump down, the officer normally dies. But, since you have all 29 he will jump down. You will then advance to the "crime scene" (Dr. Endesha's murder). The officer will open the door and tell you not to follow. Like any good soldier, go ahead and follow him. You will see the body and on the wall is the final audio log, number 30. When you access it he will attempt to kill you. Unfortunately you must put him down.
Hope this helps.
Good luck.