Reports by the police are that about 2:15 a.m. on Sunday September 23, Lyewsang and his common-law wife got involved in an argument at the family house in Rosemount.
The accused used a knife to stab his common-law wife multiple times to her upper body, then slit her throat.
He then went upstairs and attacked his 16-year-old stepdaughter, Jayshenele, also slitting her throat while she was sleeping.
The accused then took his 13-year-old son from the house, drove away from the community to St Catherine. After concealing the small boy, he then drove the vehicle into the Rio Cobre River killing himself.