Police made a breakthrough in the murder of 13-year-old Andrea Lallan and her uncle on Saturday after they charged a 27-year-old Rio Claro man for the double murder.

The development came two days after the head of the Homicide Bureau of Investigations Snr Supt Rishi Singh lamented the overall low detection rate for murders.

In addition, police said three suspects had been detained for the quadruple Guanapo murders where three children and a teenager were killed.

Another four suspects were taken into custody for separate murders, including a female suspect linked to the stabbing death of a woman in Tobago.

A police release said through the 'hard work and dedication,' the police investigators from HBI's four regions detained the suspects, who are between the ages of 19 and 49.

Of the detainees, is expected to be charged over the weekend with the murders of two fellow villagers - standard five student and her wheelchair-bound uncle Sylvan 'Puncin' Lallan, 49, of Old Mayaro Road, Libertville, Rio Claro.

The suspect of Old Mayaro Road was also expected to be charged with the attempted murder of the girl's father Eddy Lallan, 51, and having a gun and ammunition.

The charges stemmed from a shooting before dawn on September 29 at the Lallan family's home on Old Mayaro Road.

Andrea was said to be a victim of abuse. She was a student at the St Therese RC primary school.

She and her uncle died on the spot while her father was taken to hospital with gunshot wounds.

Up to Saturday afternoon, Eddy was still warded at the Sangre Grande Hospital. Funeral plans are yet to be finalised.

On Saturday, the Director of Public Prosecutions Roger Gaspard SC instructed the police to charge the suspect after reviewing a file.

A police statement on Saturday said the HBI head led investigations, which included ASP Victor, Insp Ramjag and Sgt Ramsahai Singh of Region Two.

The suspect is set to face a Rio Claro magistrate on Monday.

On Thursday, Singh said the overall detection rate for murders was about 13 per cent. He cited the unavailability of evidence as the major reason for this figure, adding that the police had solved 79 of the 454 cases by the end of September.

He gave the statistics at the press briefing at the Police Administration Building in Port of Spain.

The lone female detainee is a 49-year-old woman from Gaskin Bay Road, Bon Accord, in Tobago.

She was held in connection with the stabbing death of Rae-Ann Henry, 39, aka Lucy, on September 30, in the Crown Point police district.

Three men from Arima remained in police custody linked to the September 21 massacre in Arima that left four siblings, including a ten-year-old girl, dead and five others wounded.

The suspects are a 24-year-old man of Cemetery Street, Heights of Guanapo, Arima, a 22-year-old man of Heights of Guanapo, and a 34-year-old man of Hoyte Avenue.

The deceased victims were Tiffany Peterkin, 19, Shane Peterkin, 17, Arianna Peterkin,14, and Faith Peterkin, ten.

The relatives shot as they slept in the beds at the family's