Family's questions as cop spared jail over man's death

"They know a police officer is responsible for the death of their dad," she said, reading a victim impact statement written with her parents that a judge said eloquently outlined their heartbreak and distress.

She questioned whether the former police officer spared jail on Friday would have been treated differently if he was "not a man in uniform" and said police who knocked on the door at 5.30am to tell family Mr Roberts was dead implied it was a simple accident.

Matthew James Kelly, 52, walked out of Sydney's Downing Centre District Court on a community corrections order for the next 12 months after being found guilty of negligent driving occasioning death.

He pursued Jack Roberts, a 28-year-old father-of-two riding an unregistered Honda trail bike with no lights, up the Pacific Motorway at Blue Haven on the NSW Central Coast in the early hours of April 16, 2020, later acknowledging he had no authority to.

Mr Roberts died underneath Kelly's NSW Police Force Kia Sorrento after being knocked off the bike and run over.

Kelly assumed her brother was up to no good as he rode to work as a civil concreter, Ms Roberts said.

He was later found to have had methylamphetamine in his system but was ruled to have died from the weight of the vehicle preventing him breathing.

Kelly told responding colleagues Roberts had "come out of nowhere".

Asked if he was alright, a shocked Kelly answered: "No, not really".

Police officers spent over an hour administering CPR in an unsuccessful attempt to revive Mr Roberts, one told the trial.

A jury found Kelly not guilty of manslaughter and the alternative charge of dangerous driving occasioning death in March.

NSW District Court Judge Penelope Hock then found him guilty of the negligence charge in April.

Kelly pleaded not guilty to the charges.

"He can say whatever he likes, he was found guilty … we didn't get what we wanted, but he's a criminal," Ms Roberts told media outside court. 

Examining the same evidence as jury trials, the judge found Kelly had not driven with the required care an ordinary person would have.

"A reasonable and prudent driver would have foreseen that at night time following so closely in (his car) created a risk which was real, obvious and serious," she said.

Judge Hock convicted Kelly and placed him on a community corrections order for 12 months with his licence suspended for the same amount of time.

She said the question of personal deterrence loomed as Kelly had been caught speeding twice since being charged.

Kelly has resigned from the police force.

There was a considerable delay in convicting him, coming after two trials in front of a jury, the first of which was discharged with no verdict due to juror misconduct.

Outside court, the victim's mother Cheryl Roberts told reporters she felt her son's life was treated like it had no worth during the extended judicial process.

His father Glen Roberts recalled a police inspector coming to the house to inform them of his son's death before talking about "what a good officer (former) sergeant Kelly was".

"This was on the day of Jack's death, we haven't heard another thing since," he said.