The attacks left nine officers dead and unleashed a four-month military crackdown as soldiers swooped in to help police hunt for Rohingya militants blamed for the raids.
More than 70,000 of the Muslim minority have fled the area for neighbouring Bangladesh, bringing with them harrowing accounts of systematic rape, killings and torture at the hands of security officers.
UN investigators who interviewed escapees said the violence was so severe it “very likely” amounted to crimes against humanity and ethnic cleansing.
On Saturday a police spokesman told AFP that three senior officers were handed between two and three years in jail for allowing the raids to happen under their watch.
“Police were informed by villagers in advance before the attack. But police commanders failed to take action and rejected the information, assuming it was impossible,” said Police Colonel Myo Thu Soe.
The International Crisis Group think-tank described the October raids as the start of a new Rohingya insurgency in a region rife with tension between the stateless group and Myanmar’s Buddhist population.
The group said the attackers were recruited by a Saudi-backed network focused on advancing the political rights of the Rohingya, who have suffered under years of discrimination from a government that denies them citizenship.
After months of waving off allegations that soldiers were carrying out grave rights abuses in the recent crackdown, Myanmar’s government has recently pledged to investigate the claims.
Yet there has been little fallout for security forces so far.
Five police officers were sentenced to two months detention by an internal police tribunal over a video showing them abusing Rohingya civilians, according to police spokesman Myo Thu Soe.
Three senior police including a major were also demoted and their service terms were reduced for failing to enforce discipline.