Police arrested a fourth suspect in connection with the murder of former Special Reserve Police Officer Clevon Frederick on Sunday.
According to a police report, the 21-year-old man was held by members of the Special Operations Response Team (SORT), in Caroni during a pre-dawn exercise.
Police said the vehicle along with its three other occupants, who are between the ages 17 to 27 years, were taken to the Cunupia Police Station, for questioning.
The murder suspect was taken to the Arima Police Station.
Last week Wednesday at about 9.30 am officers responded to a report of a shooting involving three armed suspects at Boundary Road Liquor Mart, Boundary Road Extension, Barataria.
Frederick who was on duty as an estate constable was shot during the incident and died at the Mt Hope hospital.
Officers of the Central Division Operation Unit and Criminal Investigation Department later trailed the getaway car to River Branch Road, Kelly Village.
Police shot at killed a suspended soldier Vernon "Boom" Simon in that raid after they claimed they were shot at. Simon relatives challenged the police's version of the incident and have called for an investigation.
Another suspect, who police described as a 40-year-old man was shot and wounded then. He was taken to the Chaguanas District Health Facility where he was treated.
Two suspects were detained by police and taken in for questioning.
Police said they recovered a Glock pistol and a quantity of ammunition in the raid.