Law of the Twelve Colonies (RDM)
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There are many legal precedents and laws that bound the Twelve Colonies of Kobol together, as well as methods of trying people under said laws. This article highlights how the laws are treated by the Colonials before and after the Fall of the Twelve Colonies.
Articles of Colonization
The Articles of Colonization are the Twelve Colonies' constitution and guarantee its citizens basics rights. They were ratified after the Cylon War.
Amnesty, Pardons and Commutations
The President has the authority to grant amnesty and pardons, and may have a full range of options for extending executive clemency. Before the Cylon attack, President Richard Adar offers Tom Zarek a full pardon for his crimes if he will renounce violence; Zarek declines ("Bastille Day"). President Laura Roslin grants amnesty to humans in the Fleet who aided or cooperated with the Cylons on New Caprica, ("Collaborators"), and Acting President Lee Adama grants amnesty to the Final Four humanoid Cylons ("Revelations").
The express language of the U.S. Constitution confers upon the President the power to grant "reprieves and pardons". This language has been broadly construed to include "pardons, conditional pardons, commutations of sentence, conditional commutations of sentence, remissions of fines and forfeitures, respites and amnesties". Similar language in the Articles of Colonization may explain Laura Roslin's decision to use the language "general pardon" to describe the amnesty she granted in "Collaborators".
Citizens of the Colonies may ask for asylum from the military. Rya Kibby, a 17 year old Gemenese woman, sought and successfully gained asylum from the Colonial Fleet's highest ranking officer, Admiral Adama.
The result of asylum in Kibby's case was the successful abortion of her pregnancy, despite her parents' wishes (The Captain's Hand).
Recreational drug use
Prior to the First Cylon War, the Colonies passed legislation regarding the legalization of recreational drugs, such as opium. This came as a result of decades of fierce debate amongst the Twelve Colonies, which effectively removed the profit motive from drug runners and their ilk (Gravedancing). Results of this legislation can be seen in the operation of opium dens on Caprica (The Reins of a Waterfall).
While the legislation regarding drug use is unspecified in the period following the Armistice and prior to the Fall of the Colonies, legal consequences of recreational drug use are not available ("Unfinished Business", "Razor").
Prior to its resurgence post-Fall, abortion is an issue heavily contested in the Colonies, despite its legalization. In particular, the Gemenese argue against the practice on religious grounds; Laura Roslin makes the claim that she has fought for women's reproductive rights for her entire political career, and would not concede to Representative Sarah Porter's demands regarding Kibby.
As a result of population projections provided by Gaius Baltar, which highlighted the necessity of repopulating the human species, Roslin overturned the abortion laws thus making it illegal for abortions to happen anywhere in the Fleet (The Captain's Hand).
Each colony has their own laws as part of their autonomy from the federal government. For example, on Gemenon, children are legally owned by their parents until they are 18 years of age (The Captain's Hand).
Moreover, prior to Gaius Baltar's trial for collaboration with the Cylons, there is debate among the Fleet's leadership and judicial experts under which colony's law he should be tried. This implies the absence of a federal criminal code. The lack of a comprehensive law library of all colonies, but Adama having some of his father's legal books, may have resulted in the use of Caprican law (A Day in the Life).
The Cylon faction that allied itself with the Colonial fleet after the Cylon Civil War broke out insisted upon being made citizens in exchange for augmenting the fleet with their technology (A Disquiet Follows My Soul).
The allied Cylons were given a seat on the Quorum of Ships' Captains, filled by a Number Six named Sonja. They remained semi-autonomous, as evidenced by the fact that Sharon Valerii was released to them to be tried for treason against her own people (Someone to Watch Over Me).
Colonial law knows jury trials as well as tribunals. The right to a trial before a jury of one's peers seems to be guaranteed by the Articles of Colonization (Collaborators, Taking a Break From All Your Worries). However, Gaius Baltar is tried by five judges, who are randomly selected from the Fleet's ships' captains (Crossroads, Part I & II). The confusion prior to Baltar's trial suggests that no serious civilian legal framework exists within the Fleet, at least on a federal level.
The prosecution and defense of the accused is conducted by attorneys and sometimes legal aides. 
During the second term of President Laura Roslin, she institutes various emergency and secret provisions for the survivors. Some of these are minor and hardly of notice, while others are potentially consequential to the civil liberties within the Fleet.
Such provisions can be, and have been, challenged by the Quorum of Twelve at their choosing and include the following: