Mr Winchester, the Australian Federal Police assistant commissioner, was gunned down in the driveway of his neighbour's Deakin home about 9.15pm on January 10, 1989.

Police immediately launched a full scale investigation into the assassination.

Mr Eastman was one of several suspects police pursued in the aftermath. Investigators installed bugs in his Reid flat and officers conducted overt and covert surveillance of his movements.

Mr Eastman, 72, is on trial in the ACT Supreme Court for the murder. He has pleaded not guilty.

The court has previously heard Mr Eastman became frustrated with the police attention, which continued for more than a year.

Last month, lead investigator Richard Ninness told the trial that, in response, Mr Eastman began "seeking out the surveillance operators and acting very aggressively".

The court on Monday heard of a number of incidents in mid-1990 when Mr Eastman threw stones at an officer or police vehicles.

In one incident, Mr Eastman had confronted Paul Spooner, who had been following the defendant on a bicycle, in Civic before throwing a stone, which struck the officer in the hip.

On another occasion, in June 1990, the court heard Mr Eastman had cracked the windscreen of an unmarked police car that had followed him while he went to buy a newspaper.

Mark Rotherham, who gave evidence via videolink, described driving past Mr Eastman three times as he walked on Ainslie Avenue about 9.35pm.

On their third pass, he said Mr Eastman put his hand in his pocket, before making a "throwing motion".

He said he then heard an "almighty crack … [and] the windscreen had cracks in it".

Mr Rotherham said he left the area, before stopping soon after to check the damage.

The jury heard he found a seven centimetre rock wedged under the windscreen wiper.

Mr Rotherham also recalled a second occasion when Mr Eastman had thrown a projectile at a police vehicle.

He said the object – which he described as a small chunk of brick - had missed on that occasion.

Under cross-examination, Mr Rotherham denied police had used a videocamera to record Mr Eastman before the incident that damaged the windscreen.

He also denied sticking up his finger or thumb toward Mr Eastman or reversing quickly to cause tyres to screech while conducting surveillance on other occasions.

In a third incident, Anthony Fisher had parked an unmarked police car after following Mr Eastman into Civic.

He said he had begun to drive away after he saw Mr Eastman walk towards him, when the defendant threw a rock that struck the windscreen.

Mr Fisher said he drove off and reported the incident, however, he did not see the rock or the impact.

The trial continues.