The Kovan murder suspect, 34-year-old Singapore policeman Iskandar Rahmat, was taken by police to the crime scene at Hillside Drive at about 2.15pm on Saturday.
He spent about 10 to 15 minutes in the terrace house that belonged to murder victim Mr Tan Boon Sin before being driven away at 3pm in the same unmarked police car in which he arrived.
Neighbor Mr Sam Toh said that Iskandar appeared calm, muscular, and about 1.7m tall.
His feet and hands were handcuffed, said the 53-year-old, a coffee shop owner.
Neighbors who could see the action in 14J said that officers were measuring different parts of the house.
He was apprehended at 11.30pm last night in Danga Bay, Johor, after having fled to Malaysia at 11pm on Wednesday, the day of the murders.
Iskandar was a senior staff sergeant at Bedok police division. He has served with the force for 14 years.
Police commissioner Ng Joo Hee said at a press conference on Saturday morning that today was "a sad day for the police".