Pausanias’ motivations are largely rooted in his assault by a Macedonian nobleman named Attalus, which in turn was revenge for Pausanias having killed a rival lover of Philip. After seeking justice, the king chose to merely send the attacker away to take command of his armies in Anatolia, while Pausanias was awarded the position of a royal bodyguard. The latter hated this arrangement, as he felt the crime had gone unpunished (via Britannica). After the assassination, nothing more than that motive could learned from Pausanias himself, as he failed to escape the blades of the other six guards. 

There are no definitive links between Pausanias and those who intended to use his volatile anger for their political gain, including Persian king Darius III, whom Alexander (above) blamed. That being said, the bodyguards who silenced Pausanias were friends of Alexander, and intentionally or not, Alexander certainly wound up benefiting from the murder. He, and not his father, came to effectively rule the entire known world (from a Greek perspective) within a decade. If there was a conspiracy to make Alexander king, it’s also possible that Alexander himself was not aware of it. According to Pothos, Queen Olympias gave Pausanias, her husband’s murderer, proper funerary rites and an ornate tomb, possibly a posthumous reward for his deed.