Jake Pärson, the six-month-old son of inmate Denny Pärson, is played by Leonard Månsson, who actually is the son of Kalle Lind, writer of "Häktet". Lind said in an interview that he chose his son for the part because "he didn't want to traumatize another child (than his own)".
Writer Kalle Lind has actually worked as a guard, both in prison and in custody. He claims that most of the spectacular scenes and characters are taken from real life.
The character Kennet Ahl and the appearance of actor Anders Lönnbro (and, in fact, his son Harald Lönnbro - playing Kennet's son) is meant as an hommage to novels "Grundbulten" and "Lyftet" and, especially, the movie "Lyftet", all from the '70s. Anders Lönnbro played the character Kennet Ahl in "Lyftet" (also written and directed by the writer's team named Kennet Ahl, in which Anders Lönnbro was a part - a bit complicated). Writer Kalle Lind put in the character to make "a Tarantino". In fact, also the appearance of actor Henric Holmberg is a reference to a Swedish prison film from the seventies. Holmberg had a minor part in the famous "Släpp fångarne loss, det är vår" (1975) by Tage Danielsson.