Joran van der Sloot has been called a psychopath and a cold hearted killer.
Melody Granadillo dated van der Sloot shortly before Natalee Holloway disappeared five years ago. She even shares the same birthday as Natalee.
She says she nicknamed van der Sloot "chi-chi" and "Mr. Wiggles."
In an exclusive interview airing Friday on 20/20 she shows off a diary the teenaged lovers kept together, full of notes and poems.
One note written by van der Sloot says "I wrote this poem for someone I love. She knows who she is."
20/20 anchor Chris Cuomo read an excerpt from another entry by van der Sloot, saying, "I can't say how much I love you, but it's definitey the utmost. I get jealous of other guys hitting on you. I never get jealous. I think I'm afraid of losing you."
And we're learning more about Joran's life in one of the world's toughest prisons. He has made friends with a Colombian hitman nicknamed "The Clown" who is being held in the neighboring cell. They watch TV and play cards together. The Clown reportedly gave van der Sloot the nickname "Psycho."