Three family members were massacred at their home in Free Hill, Bamboo in St Ann.
The bodies of Antria Rattray, 47; her 13-year-old son, Mykah Bonnito, and her 50-year-old cousin, Lawrence Baddal, were found on Monday morning about 8:20 am.
They were found with several wounds to the neck and other areas of the body in pools of blood.
The bodies were found by a teenager who was also residing at the premises, but was not harmed.
A motive for the killings have not been determined.