Legal Injustice
The central theme of this film is legal injustice, specifically in the false convictions of the Guildford Four and also the injustice done to the families of the victims of the pub bombings who were largely forgotten in the movie. The legal system includes both the police force investigations the bombing and the prosecution who hid eyewitness evidence deliberately from the defense. The police were seen in the movie to be bullying and mentally brutal, and also to be taking this case more seriously and treating it with more urgency than other terrorist attacks primarily because the victims in this case were police officers. The prosecutors are shown to have an agenda of their own and to be an arm of the government and the Crown rather than an independent body seeking justice.
Terrorism
Another of the movie's themes is terrorism and as well as this being the crime that Gerry is convicted of it is also presented as something that takes a large number of people to carry your. Like many other things in life the film shows that a terrorist campaign "takes a village" and it is this support system of villagers that are arrested as the Maguire Seven, which in turn introduces the theme of Gerry's relationship with his father.
Father Son Relationship
Although Jim Sheridan has called Giuseppe Conlon "a non-violent parent" which his ties to the IRA have shown to be a distortion of the truth, he is a non-violent parent in the way in which he parents Gerry and the level of bitterness that Gerry has towards his father is largely unexplained; the theme of the father/son relationship is explored in moments when the men are together, particularly in the scenes during which they are cell mates, but more so in the scenes after Giuseppe's death. Gerry finds a loyalty to his father's name and memory that have grown inside him and given him a greater understanding of the way in which he was parented.