Andorian Homeworld Security was a law enforcement agency that operated within the Andorian Empire who were responsible for security arrangements of their government.
In 2376, a number of demonstrations were reported throughout the capital and in nearly every major population center on Andoria which Homeworld Security struggled to control. (DS9 - Worlds of Star Trek: Deep Space Nine novel: Andor: Paradigm)
Brigades of these officers were responsible for overseeing any threat that was deemed to great to be faced by the local law enforcement divisions on Andor. Much of their duties were the same as those of other military units stationed around the Andorian homeworld in that they were charged primarily with the defense of the planet when facing global threats. By mandate under law, Homeworld Security's involvement in operations were minimal and they were often relegated to either assistance or relief effort missions in the event of natural disasters. During such times, they were only capable of operating after being an active order from the Presider. They also had the authority to call upon military assets for other reasons which included any threat to public safety even if it was believed to be within the scope of the police force. (ST - Typhon Pact novel: Paths of Disharmony)
In 2382, following the Borg Invasion, the devastation to the planet and ongoing genetic crisis surrounding the species ability to procreate led to wide scale unrest across Andor with growing anti-Federation sentiment spreading. This saw Homeworld Security being dispatched to aid in security arrangements with them being present during a conference where talks were to begin between the Presider and Starfleet diplomatic officials. However, there was growing worry that Homeworld Security was being used to take over a role that belonged to the planetary police force. (ST - Typhon Pact novel: Paths of Disharmony)