Earth and its colonies have a variety a law enforcement institutions, all with separate areas of expertise and responsibilities, though there is some overlap and conflict does happen concerning jurisdiction. The following are some particularly more common agencies encountered in United Earth Alliance space:
Commerce Transport Authority (CTA)
A very large and influential organization with many branches, the CTA polices trade and trading hubs throughout the Human Sphere, with some contacts within the Coalition and some alien governments. CTA trains and provides starport security throughout the Human Sphere, but like other similar organizations are highly overstretched outside Earth proper and certain Inner Sphere worlds. They are a big proponent of the Alternative Regulation Mandate of 2837 (ARM Law) that greatly expanded bounty hunting outside of Earth proper, often offering bounties for stolen merchandise or the capture of thieves. Pirates, mutants and heavily armed outlaws on the other hand fall outside of their purview and they usually require cooperation with other agencies for enforcement; however in the Sol system the CTA does have a significant fleet presence not unlike a ‘Coast Guard’.
Alliance Security Police Commission (SP, or simply ‘Security Police’)
The primary security arm of the Earth Alliance, they are the main international, intercolonial, and interstation security force. They work both as uniformed officers and plainclothes detectives enforcing Alliance law and investigating cross-border and cross-system crime. Each local police organization is technically a branch of the SPs though various local traditions do cause jurisdictional issues with the Alliance-level general service. They are very prominent on Earth, though distant colonies have limited SP presence wherein they need to deputize locals (Security Auxiliary) and rely on bounty hunters and sometimes the Starfleet to enforce justice.
Center for Privacy and Safety (CPS)
The CPS agents are the successors to the dreaded ‘Thought Police’ of the 27th Century. While they have never really been able to live it down, their job is essentially the same: locating and policing rogue telepaths which are a threat to an individuals privacy. Unlike their predecessor, they are held to significant oversight and do not have as wide an authority. Government agents who come from the Academy and do military espionage work are not generally veterans of the CPS. The Guild keeps such links very limited to prevent a concentration of telepathic power.
Earth Enviromental Enforcement Agency (E3A)
Polices enviromental violations on Earth proper. They have no authority on the other colonies, however are often brought in to advise.
EarthForce Starfleet and Colonial Marines
EarthForce’s job is not law enforcement, but sometimes they are forced to assist against pirates and more dangerous adversaries the CTA, SP’s or other agencies simply can’t handle.