Perhaps she feels indebted to him for helping her

I believe Elliot is in prison because of what he did to Krista's jerk boyfriend in season one. I felt like there was a lot of emphasis on Krista in the episode and that is why she has agreed to see Elliot in prison all along. The old boyfriend character is also perfectly out of sight out of mind to the viewer. I…

I believe he is in prison for messing with Krista's boyfriend in season one