Immediately prior to his assignment as DIGP, Sabiiti, at the rank of brigadier, served as the Commander of the Military Police of the Uganda People's Defence Force (UPDF).
Sabiiti's father Zekeriah Muzeyi Magyenyi was married to one of Museveni’s maternal aunties.
He then enrolled into graduate school and lectured part-time on the advice of family members, before returning to the PPU.
When PPU was renamed Presidential Guard Brigade (PGB), with first-son Muhoozi Kainerugaba at the helm, Sabiiti Muzeyi was selected as his second-in-command.
Sabiiti, at the rank of lieutenant colonel, commanded the unit, when Muhoozi was in South Africa, attending a military course.
On the evening of Sunday 4 March 2018, he was appointed Deputy Inspector General of Police, to deputize Martin Okoth Ochola.