A Northern Rivers police officer who has pleaded not guilty to a common assault charge has disagreed with a suggestion he was in a "heightened state", was "frustrated" and "lost self-control".

Michial Luke Greenhalgh has been defending an allegation six baton strikes he inflicted upon a 16-year-old boy in Byron Bay was an unreasonable use of force and constituted common assault.

The charge arose from a January 11, 2018 police operation during which he and three colleagues detained a teen in Lateen Lane in Byron Bay.

When DPP prosecutor Brittany Parker asked Sen-Constable Greenhalgh if he "assumed the young person was going to be violent" and if he was in a "heightened state", "frustrated" and "lost self-control", he said this was not the case.

He also denied he "assumed" the teen would be violent, when asked by Ms Parker.

Evidence in the case against him wrapped up before Lismore Local Court on Tuesday and closing submissions are expected to begin on Wednesday morning.

Ms Parker suggested to the defendant, in cross-examination, the final six baton strikes he inflicted went too far

"I suggest those final six strikes were excessive, it was an entirely unreasonable use of force," she said.

Sen-Constable Greenhalgh replied: "I completely disagree".

"At no point was he struck when we had complete control of him," he said.

The court has heard the teen was "sweating profusely" and was severely drug-affected after accepting a beer from a group in Apex Park.

The alleged victim and his mother, other police officers involved, and a range of civilian witnesses gave evidence.

Four defence witnesses appeared on Tuesday to speak to the defendant's character.

Former Tweed Byron Police District commander, Superintendent Wayne Starling said he was "probably one of the finest police officers" he had worked with.

Detective chief inspector Matt Kehoe recalled an incident where the mother of a newborn phoned the police station distressed after she found a large snake around her baby's cot.

He said Sen-Constable Greenhalgh kept the mother on the phone while police were on their way and "went above and beyond what perhaps some other officers might have done to reassure that lady".

Closing submissions will begin on Wednesday morning.



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