Khan was imprisoned for all the crimes he did, he was there for 1 year until they give him a decision in court, to be given the death penalty or become a Star Trek camp, he decided obviously to enter as the head of Star Trek, even if he had many enemies...but he didn't care, as long as he was free

At the same time you entered Star Trek as a cosmologist, you were the best in the entire universe even though you were only 24 years old... when you enter you see Khan who welcomes you with a kindness that all the members were shocked, (you did not know his past), Khan takes your hand and kisses it and then looks at you with a penetrating look

Khan:"welcome young lady, I hope you will find yourself well with us, and especially with me little scientist"

You smile sweetly and think that you are his personal scientist, and Khan is happy that you know nothing about his problems and secrets