Updating and beginning this shortly.
Mars
The first settlers on Mars arrived in 2040 in the form of Russian and Chinese Cosmonauts. The stayed for 4 years constructing living habitats and artificial gardens and greenhouses.
By 2060 their was a large civilian population on Mars filling all sorts of jobs now created by the perpetual increasing of Cosmonaut missions and numbers.
Unlike the Cosmonauts these people were entirely untrained in space flight and its related studies. They filled roles such as catering and cleaning and all the other menial tasks that are required on a fixed and established settlement.
Every few months another biosphere was finished, containing people, industry and living space along with essential services including commercial exploitation by local merchants.
It was then that the Zarks were discovered, a pseudo humanoid/insect race whom, it later to light, had been living underground on mars for over 200 years. They sought to use minerals which were abundant on Mars but not on their homeworld to power their underground settlements. Every few years a mothership arrives to take back a shipment of the minerals to the homeworld for use there.
At first the Zarks were feared by the colonists, but then a Zark diplomat approached the Earth Government directly and proposed a trade; Zark Fusion powerplant technology for the free access of Mars for both races.
The United Nations convened and agreed that it was for the good of mankind that this deal go ahead, and so the Zarks were integrated into Martian society. Some Zarks and Humans disagreed, believing Mars should be taken by force. However neither side wanted a war, and so far from their homeworlds.
However the first crime began to emerge on Mars, as hate crime. After this reports of theft, assault and drug related crime rose dramatically amongst both races.
The Martian Police Department was then formed, to ensure security on Mars for both races and continued prosperity and co operation. At first gun control was easy, but during a great recession in 2072 caused as oil prices rose above acceptable levels many weapons were imported from the USA. The rise in arms smuggling to Mars was decided to be due to fear that the mineral would be seized by the Earth Government therefore robbing the Martians of their only resource and income. Or that the Zarks may take the turmoil on Earth as a weakness, and take control of Mars for themselves.
The Zark Fusion Reactors were few and far between, the UK had one, as did China and Russia. The USA was unable to get access to one after their nation collapsed into anarchy in 2071. Resources of the mineral used in the reactors was exclusive to Mars, and shipping it back and forth was extremely expensive and inefficient. Earth had no motherships as the Zarks did.
Despite all this, the Russians and Chinese still managed to field three shipments a year to Mars, bringing back goods and delivering more. Companys could pay to have a space in the cargo hold for their product, and for advertising on the broadsides.
Despite this, the Earthlings have no real weapons in space, aside from conventional missiles and ICBM's. It is also rumored their are several Ex-United States nuclear warheads made it onto Mars.
Despite all this, Mars remains relatively stable. The mineral they provide is needed at both Homeworlds and the demand only rises year by year in spite of the turbulence. The Martian PD however have the unenviable job of policing two different races by two different legal systems on a planet 371 million Km from Earth.