The Judiciary branch of a Mars settlement will be developed as the settlement grows. Magistrates may be able to carry out most of the judiciary functions of society. The availability of transportation back to Earth may offer an interesting alternative in cases where the local authorities cannot provide sufficient expertise. In particular during the early stages of the settlement, when a specific Martian identity is not yet fully developed and Martian law is still undefined.
Space law already exists regarding the ownership of land on Mars, as well as production and living facilities.
The United Nations office for Outer Space Affairs may eventually provide some services for the Mars colony.
Crimes and misdemeanors
Not all crimes have the same gravity or consequences. On Mars, damage to life support systems may be particularity targeted as grave crimes, since the environment is not self supporting, as it is on Earth.
Space law presently defines space as the common property of all mankind, and was proposed in the context of exploration rather than exploitation of resources. In the future, Martians may wish to have access to private property of land or of resources. This may be achieved by recognizing the occupants of Mars as members of a state or nation, with local laws and property.