A grandmother, said to be in her late 70s, and her caregiver were brutally chopped to death in the Harmony Hall community, Central St Mary last evening, in what investigators have termed one of the most bizarre and dastardly incidents committed in the area in recent years.

Last night, police were reported to have captured the suspect, known only as Ian, or John, who is said to be mentally challenged.

Police named the victims as Ruby White and her caregiver Philomenia Spence, said to be in her 40s.

White was chopped all over her body and then dragged from her house into her yard, while Spence's body was left in the house, next to the Amritt Basic School, two kilometres west of the bustling and fast-growing town of Highgate.

A third woman, who is said to be the mother of the accused man, and who was identified only as 'Sister Fay', was also chopped all over her body in her house next door. She was rushed to hospital in serious condition.

Scores of curious onlookers gathered outside the death house last night, while police searched desperately for clues.

"Bwoy, me no know a wha fly up ina da bwoy de head why him chop up the people so," one resident told the Observer.

"Me never know sey things like this coulda happen a Harmony Hall," said another.

Residents told the Observer that White was the step grandmother of the accused man. She was said to have helped to raise him, but had challenges throughout because of his mental condition, which at times resulted in intermittent unstable conduct.