Investigations are continuing into the deaths of retired Police Corporal Kenneth Machan and his wife Leela Marchan.
The two were found dead at their Cunupia home on Monday morning.
Their bodies were badly decomposed.
The Police Social and Welfare Association is expressing its sadness at the passing of a former colleague.
General Secretary Ancil Forde said yesterday he is confident whoever is responsible will be held.
Mr. Forde also called on people to be vigilant.
One man was held for questioning after he was reportedly found driving the car, which belonged to Mr. Marchan.