The County Court heard Samuel James Miller was a detective senior constable attached to the Bendigo Crime Investigation Unit in November 2014 when he was allocated an investigation into a serious assault on a man.

The following March, Miller recorded in the investigation database that he had requested a further statement from the victim, who wished to withdraw his complaint, and no further investigation was required.

Miller's superior then marked the investigation as completed.

In December 2017, a 14-year-old boy was shining laser pointers at cars with friends in Bendigo when a vehicle stopped and the occupants caught him and directed him to get inside.

They drove him to Lake Weeroona and assaulted him, kicking him in the stomach and leg.

Later that day, Miller received the file and spoke to the victim and his mother.

Crown prosecutor Matt Fisher said Miller developed the belief the boy was not being completely truthful with him, and subsequently formed a bias against him.

The following month, Miller made an investigation report entry that the boy had recanted his statement and knew the offenders, writing that it was likely related to a drug dispute.

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Then in March 2018, he uploaded a statement of no complaint purportedly signed by the victim to the investigation database, which led to the closure of the investigation.

That February Miller began investigating another serious crime, this time an aggravated burglary and assault against a woman.

In an entry in his official police diary, Miller wrote that the victim was uncooperative.

Again a statement of no complaint signed by the victim was filed and Miller alleged she wanted no further investigation.

He recommended the investigation be closed.

But Mr Fisher said there was no evidence Miller had tried to contact the victim nor talk to the suspects.

In April 2018, the court heard, it became clear the statement of no complaint purportedly signed by the third victim was created by Miller.

A comparison of the signature on this statement against that on the victim's first statement to police revealed they were identical.

Mr Fisher said Miller made the statement so his supervisor would end the investigation.

Miller was arrested in relation to this matter and made full admissions, telling officers the victim was uncooperative and the matter was not worth his time investigating.

He told the officers it was the only time he had acted in such a way.

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But the Professional Standards Command investigation subsequently uncovered similar conduct in relation to the assaults against the man and the teenage boy.

Miller again confessed to this offending, saying he perceived the boy to be untruthful and uncooperative.

An audit of Miller's file in the database revealed a JPEG image that was a scanned copy of the boy's signature.

Again, the signature on the statement of no complaint was an exact copy of that on the victim's original statement.

All three victims said they had not withdrawn their complaints or signed statements of no complaint, and had believed the investigations into their matters were ongoing.

This week, Miller pleaded guilty in the County Court to three charges of misconduct in public office.

Defence counsel Jason Gullaci conceded the crime was serious, but submitted "there are far more serious examples of this offence involving police officers that routinely come before this court".

Mr Gullaci said his client felt there was a lack of interest and cooperation from the victims when he tried to speak to them, and he became increasingly frustrated.

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The court heard Miller told a psychologist: "Really, it was probably more laziness than dishonesty".

He also said it was "just stupidity".

Mr Gullaci said his client was suffering depression and anxiety at the time of the offending, and while it did not excuse his actions, it provided context.

He said there was evidence to support his client's allegations that the victims were difficult to get hold of or potentially untruthful.

Miller had acknowledged the "inappropriateness" of his actions in his first police interview, Mr Gullaci said, and voiced disappointment in himself.

The court heard Miller was suspended from Victoria Police without pay, but the matter would end his policing career.

Mr Gullaci said his client had a "very good work ethic", continued to receive treatment for his mental health, and had strong support.

"Despite the seriousness of the offences... it is submitted that he can be adequately punished by the imposition of a community corrections order," Mr Gullaci said.

Mr Fisher agreed, although said Miller's offending constituted a very serious breach of trust that could undermine confidence in police and the administration of justice.

Miller will be sentenced next week.

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