The Crown has entered a third day of closing arguments in the case against Mr Eastman, 73, who has pleaded not guilty to shooting the police chief in the head on January 10, 1989.

Prosecutor Murugan Thangaraj SC told the jury that if it wasn’t Mr Eastman who neighbours saw two nights before the murder, then it was another person with a very similar car to Mr Eastman.

It was a car with the same body type, shape and colour, someone who had parked under the darkest spot in the area, within view of the Winchester home on Lawley Street, with number plates that had four characters in sequence that matched those of Mr Eastman, and it was a person who tried to hide when people walked past, in a car that neighbours had never seen in the area and would not see again, he said.

The prosecutor also played tapes to the ACT Supreme Court jury of Mr Eastman’s mutterings recorded by police bugs when he was alone in his flat, saying they were admissions of his visits to Lawley Street.

He said Mr Eastman had said to himself “then you go back the following night” in the same car, the same registration and the same driver, and then “finally on the second night you succeeded”.

Mr Thangaraj also said Mr Eastman was captured saying he had to come back and “kill the bugger” and “all of a sudden he was dead”.

He observed that cross-examination of a neighbour who said he heard a car that sounded like a V8 was designed to suggest a member of the mafia - who had access to a V8 car - used a very loud car to go murder a police chief and “to be as inconspicuous as possible”.

Mr Thangaraj argued it also took leaps of logic to say that because the mafia member had access to a V8 he had used it that night.

He said without significant speculation there was nothing to link the sound to the mafia.

Later on Wednesday, Mr Thangaraj turned to the topic of the crime scene and the thoroughness of the police investigation.

He also refuted any suggestion that the large number of people who were present in the crime scene would have compromised the evidence.

He said the hard ground and short grass would not have turned up footprints, and that tests had shown a 99 per cent chance of finding no fingerprints on spent cartridges.

There was a basically nil chance of uncovering enough fingerprint detail to compare, he said.

The crime scene officers had fingerprinted everywhere it was possible to be done, he added.

"This was not an ordinary murder by any stretch of the imagination," he said.

He told the jury that the officers involved, including Commander Richard Ninness, "would be very motivated to find the person who did this, the right person who did this."

The trial continues.