This can be done by pure luck/ getting caught or by grinding.
This means that you have to be in solitary for 72 in-game hours, I am not sure if it only counts if you have a time to wait in the bottom right corner.
When you press down on the D-Pad you can "Surrender", You will be automaticaly be put in solitary for a minimum of 3 minutes/hours. To get 72 hours you will have to this 24 times to get the achievement.