Roger Caine was a Sergeant and also the best friend to fellow Marine, Sergeant William Moore.
While Sergeant Moore was serving in Iraq, Roger and Judy grew closer and as such, began sleeping together. This would later come back to haunt them when all three of them went on a camping trip and Sergeant Moore caught evidence of Judy touching Roger's face on his camera.
Unfortunately, Sergeant Moore was killed a few hours later and after a lengthy search, the Major Case Response Team found out about Roger and Judy's affair, resulting in Leroy Jethro Gibbs in interviewing the two of them separately in hopes of getting them to reveal their guilt.
After much talk, Roger and Judy were left steaming in the same interrogation room where Roger told her that he regretted their affair with Judy going on to say that she was pregnant with Roger's baby.
The two were found not guilty but Gibbs opted to let them suffer for a while, saying Sergeant Moore would appreciate it.