As the patrol car travelled over the Tauranga Harbour Bridge, Kemp bit down on the top of the first victim's hand.
A struggle ensued, during which Kemp kicked at the same officer and pinned the sergeant to the patrol car door by his throat.
Kemp held his foot against this victim's throat with enough pressure to restrict his breathing before the officer elbowed the defendant to free himself.
Kemp then spat at the second victim, who was driving the patrol car, and bloody spittle landed on one officer's face and the other's arm.
The knife possession charge came after Kemp was stopped by police on April 24 after he left his mother's home in an agitated state. He had a large hunting knife in his car.
Kemp told his mother he had been beaten up and robbed by a group of people, and wanted to stab someone with the hunting knife, the court heard.
His lawyer William McNicol told Judge Bill Lawson his client was now taking medication to address his mental health issues and addictions.
Kemp's letter of apology showed he was "thinking more clearly" and regretted his actions, McNichol said.
"It seems Mr Kemp was screaming out for help to address his serious mental health issues and he was seen by the forensic team in prison.
"It seems his head is a lot clearer and he wants to address his problems. His addictions were to escape the rigours of what Mr Kemp had to go through this year."
Kemp lost his father this year, his mother had terminal cancer, and he accepted he "absolutely lost the plot'" when he assaulted the officers, McNicol said.
McNicol urged Judge Lawson to take into account the fact that Kemp was making "quite good progress" in addressing the causes of his offending, and to remit his $3587 fines.
Judge Lawson told Kemp the two police officers in their victim impact statements both wrote they were "sick of people like you" lashing out at them.
"I certainly have some sympathy for them and agree entirely that they shouldn't have to put up with this aggressive treatment while going about their lawful duties. It was absolutely disgusting and appalling behaviour."
However, Judge Lawson said he was prepared to accept Kemp was ashamed of his behaviour and had shown some insight into his offending.
The judge sentenced Kemp to 14 months in prison, stopped his fines and imposed six months of prison release conditions.